firebird-mirror/src/dsql/pass1.cpp

/*
 *	PROGRAM:	Dynamic SQL runtime support
 *	MODULE:		pass1.cpp
 *	DESCRIPTION:	First-pass compiler for statement trees.
 *
 * The contents of this file are subject to the Interbase Public
 * License Version 1.0 (the "License"); you may not use this file
 * except in compliance with the License. You may obtain a copy
 * of the License at http://www.Inprise.com/IPL.html
 *
 * Software distributed under the License is distributed on an
 * "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, either express
 * or implied. See the License for the specific language governing
 * rights and limitations under the License.
 *
 * The Original Code was created by Inprise Corporation
 * and its predecessors. Portions created by Inprise Corporation are
 * Copyright (C) Inprise Corporation.
 *
 * All Rights Reserved.
 * Contributor(s): ______________________________________.
 *
 * 2001.5.26: Claudio Valderrama: field names should be skimmed from trailing
 *
 * 2001.5.26: Claudio Valderrama: COMPUTED fields will be skipped if a dummy
 *       "insert into tbl values(...)" sentence is issued.
 *
 * 2001.5.26: Claudio Valderrama: field names should be skimmed from trailing
 *		blanks to allow reliable comparisons in pass1_field. Same for table and
 *		and index names in plans.
 *
 * 2001.5.29: Claudio Valderrama: handle DROP VIEW case in pass1_statement().
 *
 * 2001.6.12: Claudio Valderrama: add basic BREAK capability to procedures.
 *
 * 2001.6.27: Claudio Valderrama: pass1_variable() now gives the name of the
 * variable it can't find in the error message.
 *
 * 2001.6.30: Claudio Valderrama: Enhanced again to provide (line, col), see node.h.
 *
 * 2001.7.28: John Bellardo: added code to handle nod_limit and associated fields.
 *
 * 2001.08.14 Claudio Valderrama: fixed crash with trigger and CURRENT OF <cursor> syntax.
 *
 * 2001.09.10 John Bellardo: fixed gen_rse to attribute skip/first nodes to the parent_rse
 *   if present instead of the child rse.  BUG #451798
 *
 * 2001.09.26 Claudio Valderrama: ambiguous field names are rejected from now.
 *
 * 2001.10.01 Claudio Valderrama: check constraints are allowed to have ambiguous field
 *   names because they use OLD and NEW as aliases of the same table. However, if the
 *   check constraint has an embedded ambiguous SELECT statement, it won't be detected.
 *   The code should be revisited if check constraints' before delete triggers are used
 *   for whatever reason. Currently they are never generated. The code can be improved
 *   to not report errors for fields between NEW and OLD contexts but complain otherwise.
 *
 * 2001.10.05 Neil McCalden: validate udf and parameters when comparing select list and
 *   group by list, to detect invalid SQL statements when grouping by UDFs.
 *
 * 2001.10.23 Ann Harrison:  allow reasonable checking of ambiguous names in unions.
 *   Remembering, later, that LLS_PUSH expects an object, not an LLS block.  Also
 *   stuck in the code for handling variables in pass1 - it apparently doesn't happen
 *   because the code returned an uninitialized pointer.
 *
 * 2001.11.17 Neil McCalden: Add aggregate_in_list procedure to handle cases
 *   where select statement has aggregate as a parameter to a udf which does
 *   not have to be in a group by clause.
 *
 * 2001.11.21 Claudio Valderrama: don't try to detect ambiguity in pass1_field()
 *   if the field or output procedure parameter has been fully qualified!!!
 *
 * 2001.11.27 Ann Harrison:  Redo the amiguity checking so as to give better
 *   error messages, return warnings for dialect 1, and simplify.
 *
 * 2001.11.28 Claudio Valderrama: allow udf arguments to be query parameters.
 *   Honor the code in the parser that already accepts those parameters.
 *   This closes SF Bug# 409769.
 *
 * 2001.11.29 Claudio Valderrama: make the nice new ambiguity checking code do the
 *   right thing instead of crashing the engine and restore fix from 2001.11.21.
 *
 * 2001.12.21 Claudio Valderrama: Fix SF Bug #494832 - pass1_variable() should work
 *   with def_proc, mod_proc, redef_proc, def_trig and mod_trig node types.
 *
 * 2002.07.30 Arno Brinkman: Added pass1_coalesce, pass1_simple_case, pass1_searched_case
 *   and PASS1_put_args_on_stack
 *
 * 2002.08.04 Arno Brinkman: Added ignore_cast as parameter to PASS1_node_match,
 *   Changed invalid_reference procedure for allow EXTRACT, SUBSTRING, CASE,
 *   COALESCE and NULLIF functions in GROUP BY and as select_items.
 *   Removed aggregate_in_list procedure.
 *
 * 2002.08.07 Dmitry Yemanov: Disabled BREAK statement in triggers
 *
 * 2002.08.10 Dmitry Yemanov: ALTER VIEW
 *
 * 2002.09.28 Dmitry Yemanov: Reworked internal_info stuff, enhanced
 *                            exception handling in SPs/triggers,
 *                            implemented ROWS_AFFECTED system variable
 *
 * 2002.09.29 Arno Brinkman: Adding more checking for aggregate functions
 *   and adding support for 'linking' from sub-selects to aggregate functions
 *   which are in an lower level.
 *   Modified functions pass1_field, pass1_rse, copy_field, pass1_sort.
 *   Functions pass1_found_aggregate and pass1_found_field added.
 *
 * 2002.10.21 Nickolay Samofatov: Added support for explicit pessimistic locks
 *
 * 2002.10.25 Dmitry Yemanov: Re-allowed plans in triggers
 *
 * 2002.10.29 Nickolay Samofatov: Added support for savepoints
 *
 * 2002.12.03 Dmitry Yemanov: Implemented ORDER BY clause in subqueries
 *
 * 2002.12.18 Dmitry Yemanov: Fixed bug with BREAK and partially implemented
 *							  SQL-compliant labels and LEAVE statement
 *
 * 2003.01.11 Arno Brinkman: Reworked a lot of functions for bringing back backwards compatibilty
 *							 with sub-selects and aggregates.
 *
 * 2003.01.14 Dmitry Yemanov: Fixed bug with cursors in triggers
 *
 * 2003.01.15 Dmitry Yemanov: Added support for parametrized events
 *
 * 2003.04.05 Dmitry Yemanov: Changed logic of ORDER BY with collations
 *							  (because of the parser change)
 *
 * 2003.08.14 Arno Brinkman: Added derived table support.
 *
 * 2003.08.16 Arno Brinkman: Changed ambiguous column name checking.
 *
 * 2003.10.05 Dmitry Yemanov: Added support for explicit cursors in PSQL.
 *
 * 2004.01.16 Vlad Horsun: added support for default parameters and
 *   EXECUTE BLOCK statement
 *
 * Adriano dos Santos Fernandes
 *
 */

#include "firebird.h"
#include <string.h>
#include <stdio.h>
#include "../jrd/ibase.h"
#include "../dsql/dsql.h"
#include "../dsql/node.h"
#include "../dsql/Nodes.h"
#include "../dsql/BoolNodes.h"
#include "../dsql/ExprNodes.h"
#include "../jrd/intl.h"
#include "../jrd/blr.h"
#include "../jrd/jrd.h"
#include "../jrd/constants.h"
#include "../jrd/intl_classes.h"
#include "../jrd/RecordSourceNodes.h"
#include "../dsql/DdlNodes.h"
#include "../dsql/StmtNodes.h"
#include "../dsql/ddl_proto.h"
#include "../dsql/errd_proto.h"
#include "../dsql/gen_proto.h"
#include "../dsql/hsh_proto.h"
#include "../dsql/make_proto.h"
#include "../dsql/metd_proto.h"
#include "../dsql/pass1_proto.h"
#include "../dsql/utld_proto.h"
#include "../dsql/DSqlDataTypeUtil.h"
#include "../common/dsc_proto.h"
#include "../jrd/intl_proto.h"
#include "../jrd/jrd_proto.h"
#include "../jrd/thread_proto.h"
#include "../yvalve/why_proto.h"
#include "../jrd/SysFunction.h"
#include "../common/classes/array.h"
#include "../common/classes/auto.h"
#include "../common/utils_proto.h"
#include "../common/config/config.h"
#include "../common/StatusArg.h"

using namespace Jrd;
using namespace Dsql;
using namespace Firebird;

#ifdef DEV_BUILD
static void DSQL_pretty(const dsql_nod*, int);
#endif


static void assign_fld_dtype_from_dsc(dsql_fld*, const dsc*);
static dsql_nod* explode_fields(dsql_rel*);
static void field_appears_once(const dsql_nod*, const dsql_nod*, const bool, const char*);
static void field_duplication(const TEXT*, const TEXT*, const dsql_nod*, const char*);
static dsql_par* find_dbkey(const dsql_req*, const dsql_nod*);
static dsql_par* find_record_version(const dsql_req*, const dsql_nod*);
static dsql_ctx* get_context(const dsql_nod* node);
static void get_contexts(DsqlContextStack& contexts, const dsql_nod* node);
static dsql_nod* nullify_returning(DsqlCompilerScratch*, dsql_nod* input, dsql_nod** list = NULL);
static dsql_ctx* pass1_alias_list(DsqlCompilerScratch*, dsql_nod*);
static dsql_ctx* pass1_alias(DsqlCompilerScratch*, DsqlContextStack&, dsql_str*);
static dsql_str* pass1_alias_concat(const dsql_str*, const char*);
static dsql_rel* pass1_base_table(DsqlCompilerScratch*, const dsql_rel*, const dsql_str*);
static void pass1_blob(DsqlCompilerScratch*, dsql_nod*);
static dsql_nod* pass1_collate(DsqlCompilerScratch*, dsql_nod*, const dsql_str*);
static dsql_ctx* pass1_cursor_context(DsqlCompilerScratch*, const dsql_nod*, const dsql_nod*);
static dsql_nod* pass1_cursor_reference(DsqlCompilerScratch*, const dsql_nod*, dsql_nod*);
static dsql_nod* pass1_delete(DsqlCompilerScratch*, dsql_nod*);
static void pass1_expand_contexts(DsqlContextStack& contexts, dsql_ctx* context);
static dsql_nod* pass1_derived_table(DsqlCompilerScratch*, dsql_nod*, const char*);
static dsql_nod* pass1_expand_select_list(DsqlCompilerScratch*, dsql_nod*, dsql_nod*);
static dsql_nod* pass1_field(DsqlCompilerScratch*, dsql_nod*, const bool, dsql_nod*);
static dsql_nod* pass1_group_by_list(DsqlCompilerScratch*, dsql_nod*, dsql_nod*);
static dsql_nod* pass1_hidden_variable(DsqlCompilerScratch* dsqlScratch, dsql_nod* expr);
static dsql_nod* pass1_insert(DsqlCompilerScratch*, dsql_nod*, bool);
static void pass1_limit(DsqlCompilerScratch*, dsql_nod*, dsql_nod*, RseNode*);
static dsql_nod* pass1_make_derived_field(DsqlCompilerScratch*, thread_db*, dsql_nod*);
static dsql_nod* pass1_merge(DsqlCompilerScratch*, dsql_nod*);
static dsql_nod* pass1_relation(DsqlCompilerScratch*, dsql_nod*);
static dsql_nod* pass1_returning(DsqlCompilerScratch*, const dsql_nod*);
static dsql_nod* pass1_rse(DsqlCompilerScratch*, dsql_nod*, dsql_nod*, dsql_nod*, dsql_nod*, USHORT);
static dsql_nod* pass1_rse_impl(DsqlCompilerScratch*, dsql_nod*, dsql_nod*, dsql_nod*, dsql_nod*, USHORT);
static dsql_nod* pass1_sel_list(DsqlCompilerScratch*, dsql_nod*, bool);
static dsql_nod* pass1_sort(DsqlCompilerScratch*, dsql_nod*, dsql_nod*);
static dsql_nod* pass1_union(DsqlCompilerScratch*, dsql_nod*, dsql_nod*, dsql_nod*, dsql_nod*, USHORT);
static void pass1_union_auto_cast(DsqlCompilerScratch*, dsql_nod*, const dsc&, SSHORT,
	bool in_select_list = false);
static dsql_nod* pass1_update(DsqlCompilerScratch*, dsql_nod*, bool);
static dsql_nod* pass1_update_or_insert(DsqlCompilerScratch*, dsql_nod*);
static dsql_nod* pass1_variable(DsqlCompilerScratch*, dsql_nod*);
static void remap_streams_to_parent_context(dsql_nod*, dsql_ctx*);
static dsql_fld* resolve_context(DsqlCompilerScratch*, const dsql_str*, dsql_ctx*, bool);
static void set_parameters_name(dsql_nod*, const dsql_nod*);
static void set_parameter_name(dsql_nod*, const dsql_nod*, const dsql_rel*);
static dsql_nod* pass1_savepoint(const DsqlCompilerScratch*, dsql_nod*);
static dsql_nod* process_returning(DsqlCompilerScratch*, dsql_nod*);


namespace
{
	class ReturningProcessor
	{
	public:
		// Play with contexts for RETURNING purposes.
		// Its assumed that oldContext is already on the stack.
		// Changes oldContext name to "OLD".
		ReturningProcessor(DsqlCompilerScratch* aScratch, dsql_ctx* oldContext, dsql_ctx* modContext)
			: scratch(aScratch),
			  autoAlias(&oldContext->ctx_alias, OLD_CONTEXT),
			  autoInternalAlias(&oldContext->ctx_internal_alias, oldContext->ctx_alias),
			  autoFlags(&oldContext->ctx_flags, oldContext->ctx_flags | CTX_system | CTX_returning),
			  hasModContext(modContext != NULL)
		{
			// Clone the modify/old context and push with name "NEW" in a greater scope level.

			dsql_ctx* newContext = FB_NEW(scratch->getPool()) dsql_ctx(scratch->getPool());

			if (modContext)
			{
				// push the modify context in the same scope level
				scratch->context->push(modContext);
				*newContext = *modContext;
				newContext->ctx_flags |= CTX_system;
			}
			else
			{
				// This is NEW in the context of a DELETE. Mark it as NULL.
				*newContext = *oldContext;
				newContext->ctx_flags |= CTX_null;

				// Remove the system flag, so unqualified fields could be resolved to this context.
				oldContext->ctx_flags &= ~CTX_system;
			}

			newContext->ctx_alias = newContext->ctx_internal_alias =
				MAKE_cstring(NEW_CONTEXT)->str_data;
			newContext->ctx_flags |= CTX_returning;
			scratch->context->push(newContext);
		}

		~ReturningProcessor()
		{
			// Restore the context stack.
			scratch->context->pop();
			if (hasModContext)
				scratch->context->pop();
		}

		// Process the RETURNING clause.
		dsql_nod* process(dsql_nod* node)
		{
			return process_returning(scratch, node);
		}

		// Clone a RETURNING node without create duplicate parameters.
		static dsql_nod* clone(dsql_nod* unprocessed, dsql_nod* processed)
		{
			if (!processed)
				return unprocessed;

			// nod_returning was already processed
			fb_assert(processed->nod_type == nod_list);

			// And we create a RETURNING node where the targets are already processed.
			dsql_nod* newNode = MAKE_node(nod_list, processed->nod_count);

			dsql_nod** srcPtr = unprocessed->nod_arg[e_ret_source]->nod_arg;
			dsql_nod** dstPtr = processed->nod_arg;
			dsql_nod** ptr = newNode->nod_arg;

			for (const dsql_nod* const* const end = ptr + processed->nod_count;
				 ptr < end; ++srcPtr, ++dstPtr, ++ptr)
			{
				dsql_nod* temp = MAKE_node(nod_assign, e_asgn_count);
				temp->nod_arg[e_asgn_value] = *srcPtr;
				temp->nod_arg[e_asgn_field] = (*dstPtr)->nod_arg[1];
				*ptr = temp;
			}

			return newNode;
		}

	private:
		DsqlCompilerScratch* scratch;
		AutoSetRestore<string> autoAlias;
		AutoSetRestore<string> autoInternalAlias;
		AutoSetRestore<USHORT> autoFlags;
		bool hasModContext;
	};
}	// namespace


AggregateFinder::AggregateFinder(const DsqlCompilerScratch* aDsqlScratch, bool aWindow)
	: ConstDsqlNodeVisitor(false, false, &ExprNode::dsqlAggregateFinder),
	  dsqlScratch(aDsqlScratch),
	  window(aWindow),
	  currentLevel(dsqlScratch->scopeLevel),
	  deepestLevel(0),
	  ignoreSubSelects(false)
{
}

bool AggregateFinder::internalVisit(const dsql_nod* node)
{
	DEV_BLKCHK(node, dsql_type_nod);
	return node && visitChildren(node);
}


Aggregate2Finder::Aggregate2Finder(USHORT aCheckScopeLevel, FieldMatchType aMatchType, bool aWindowOnly)
	: ConstDsqlNodeVisitor(true, false, &ExprNode::dsqlAggregate2Finder),
	  checkScopeLevel(aCheckScopeLevel),
	  matchType(aMatchType),
	  windowOnly(aWindowOnly),
	  currentScopeLevelEqual(true)
{
}

bool Aggregate2Finder::internalVisit(const dsql_nod* node)
{
	DEV_BLKCHK(node, dsql_type_nod);
	return node && visitChildren(node);
}


FieldFinder::FieldFinder(USHORT aCheckScopeLevel, FieldMatchType aMatchType)
	: ConstDsqlNodeVisitor(true, false, &ExprNode::dsqlFieldFinder),
	  checkScopeLevel(aCheckScopeLevel),
	  matchType(aMatchType),
	  field(false)
{
}

bool FieldFinder::internalVisit(const dsql_nod* node)
{
	DEV_BLKCHK(node, dsql_type_nod);
	return node && visitChildren(node);
}


InvalidReferenceFinder::InvalidReferenceFinder(const dsql_ctx* aContext, const dsql_nod* aList)
	: ConstDsqlNodeVisitor(true, false, &ExprNode::dsqlInvalidReferenceFinder),
	  context(aContext),
	  list(aList),
	  insideOwnMap(false),
	  insideHigherMap(false)
{
	DEV_BLKCHK(list, dsql_type_nod);
}

bool InvalidReferenceFinder::internalVisit(const dsql_nod* node)
{
	DEV_BLKCHK(node, dsql_type_nod);

	if (!node)
		return false;

	bool invalid = false;

	// ASF: What we do in this function is the verification of all fields/dbkeys (or any parent
	// expression involving them) are present in the passed node list.
	// That makes valid:
	//   select n + 0 from table group by n			=> The n item is present in the list
	//   select n + 0 from table group by n + 0		=> The n + 0 item is present in the list
	// And makes invalid:
	//   select n + 1 from table group by n + 0		=> The n + 1 item is not present in the list

	if (list)
	{
		// Check if this node (with ignoring of CASTs) appears also
		// in the list of group by. If yes then it's allowed
		const dsql_nod* const* ptr = list->nod_arg;
		for (const dsql_nod* const* const end = ptr + list->nod_count; ptr < end; ptr++)
		{
			if (PASS1_node_match(node, *ptr, true))
				return false;
		}
	}

	switch (node->nod_type)
	{
		case nod_plan_expr:
			fb_assert(false);
			return false;

		default:
			return visitChildren(node);
	}

	return invalid;
}


FieldRemapper::FieldRemapper(DsqlCompilerScratch* aDsqlScratch, dsql_ctx* aContext, bool aWindow,
			dsql_nod* aPartitionNode, dsql_nod* aOrderNode)
	: NonConstDsqlNodeVisitor(false, false, &ExprNode::dsqlFieldRemapper),
	  dsqlScratch(aDsqlScratch),
	  context(aContext),
	  window(aWindow),
	  partitionNode(aPartitionNode),
	  orderNode(aOrderNode),
	  currentLevel(dsqlScratch->scopeLevel)
{
	DEV_BLKCHK(dsqlScratch, dsql_type_req);
	DEV_BLKCHK(context, dsql_type_ctx);
}

bool FieldRemapper::internalVisit(dsql_nod* node)
{
	DEV_BLKCHK(node, dsql_type_nod);
	return node && visitChildren(node);
}


SubSelectFinder::SubSelectFinder()
	: ConstDsqlNodeVisitor(false, true, &ExprNode::dsqlSubSelectFinder)
{
}

bool SubSelectFinder::internalVisit(const dsql_nod* node)
{
	DEV_BLKCHK(node, dsql_type_nod);

	if (!node)
		return false;

	switch (node->nod_type)
	{
		case nod_field_name:
			return false;

		case nod_order:
			fb_assert(false);
			return true;

		default:
			return visitChildren(node);
	}

	return false;
}


/**

 	PASS1_make_context

    @brief	Generate a context for a dsqlScratch.


    @param dsqlScratch
    @param relation_node

 **/
dsql_ctx* PASS1_make_context(DsqlCompilerScratch* dsqlScratch, const dsql_nod* relation_node)
{
	DEV_BLKCHK(dsqlScratch, dsql_type_req);
	DEV_BLKCHK(relation_node, dsql_type_nod);

	thread_db* const tdbb = JRD_get_thread_data();

	dsql_rel* relation = NULL;
	dsql_prc* procedure = NULL;

	// figure out whether this is a relation or a procedure
	// and give an error if it is neither

	MetaName relation_name;
	const ProcedureSourceNode* procNode = NULL;
	const RelationSourceNode* relNode = NULL;

	switch (relation_node->nod_type)
	{
	case nod_select_expr:
		if (relation_node->nod_arg[e_sel_alias])
			relation_name = ((dsql_str*) relation_node->nod_arg[e_sel_alias])->str_data;
		break;
	default:
		{
			if ((procNode = ExprNode::as<ProcedureSourceNode>(relation_node)))
				relation_name = procNode->dsqlName.identifier;
			else if ((relNode = ExprNode::as<RelationSourceNode>(relation_node)))
				relation_name = relNode->dsqlName;
		}
		break;
	}

	const dsql_nod* cte = NULL;

	if (relation_node->nod_type == nod_select_expr)
	{
		// No processing needed here for derived tables.
	}
	else if (procNode && (procNode->dsqlName.package.hasData() || procNode->dsqlInputs))
	{
		procedure = METD_get_procedure(dsqlScratch->getTransaction(), dsqlScratch,
			procNode->dsqlName);

		if (!procedure)
		{
			ERRD_post(Arg::Gds(isc_sqlerr) << Arg::Num(-204) <<
					  Arg::Gds(isc_dsql_procedure_err) <<
					  Arg::Gds(isc_random) <<
					  Arg::Str(procNode->dsqlName.toString()) <<
					  Arg::Gds(isc_dsql_line_col_error) << Arg::Num(relation_node->nod_line) <<
					  									   Arg::Num(relation_node->nod_column));
		}
	}
	else if ((cte = dsqlScratch->findCTE(relation_name)))
		relation_node = cte;
	else
	{
		relation = METD_get_relation(dsqlScratch->getTransaction(), dsqlScratch, relation_name);

		if (!relation && procNode)
		{
			procedure = METD_get_procedure(dsqlScratch->getTransaction(),
				dsqlScratch, procNode->dsqlName);
		}

		if (!relation && !procedure)
		{
			ERRD_post(Arg::Gds(isc_sqlerr) << Arg::Num(-204) <<
					  Arg::Gds(isc_dsql_relation_err) <<
					  Arg::Gds(isc_random) << Arg::Str(relation_name) <<
					  Arg::Gds(isc_dsql_line_col_error) << Arg::Num(relation_node->nod_line) <<
					  									   Arg::Num(relation_node->nod_column));
		}
	}

	if (procedure && !procedure->prc_out_count)
	{
		ERRD_post(Arg::Gds(isc_sqlerr) << Arg::Num(-84) <<
				  Arg::Gds(isc_dsql_procedure_use_err) << Arg::Str(procedure->prc_name.toString()) <<
				  Arg::Gds(isc_dsql_line_col_error) << Arg::Num(relation_node->nod_line) <<
				  									   Arg::Num(relation_node->nod_column));
	}

	// Set up context block.
	dsql_ctx* context = FB_NEW(*tdbb->getDefaultPool()) dsql_ctx(*tdbb->getDefaultPool());
	context->ctx_relation = relation;
	context->ctx_procedure = procedure;

	if (relation_node->nod_type == nod_select_expr)
		context->ctx_context = USHORT(MAX_UCHAR) + 1 + dsqlScratch->derivedContextNumber++;
	else
		context->ctx_context = dsqlScratch->contextNumber++;

	context->ctx_scope_level = dsqlScratch->scopeLevel;

	// When we're in a outer-join part mark context for it.
	if (dsqlScratch->inOuterJoin)
		context->ctx_flags |= CTX_outer_join;

	context->ctx_in_outer_join = dsqlScratch->inOuterJoin;

	// find the context alias name, if it exists.
	const char* string = NULL;

	if ((procNode = ExprNode::as<ProcedureSourceNode>(relation_node)))
		string = procNode->alias.nullStr();
	else if ((relNode = ExprNode::as<RelationSourceNode>(relation_node)))
		string = relNode->alias.nullStr();
	else if (relation_node->nod_type == nod_select_expr)
	{
		if (relation_node->nod_arg[e_sel_alias])
			string = ((dsql_str*) relation_node->nod_arg[e_sel_alias])->str_data;
		context->ctx_rse = relation_node->nod_arg[e_sel_query_spec];
	}

	if (string)
		context->ctx_internal_alias = string;

	if (dsqlScratch->aliasRelationPrefix && relation_node->nod_type != nod_select_expr)
	{
		if (string)
			string = pass1_alias_concat(dsqlScratch->aliasRelationPrefix, string)->str_data;
		else
			string = pass1_alias_concat(dsqlScratch->aliasRelationPrefix, relation_name.c_str())->str_data;
	}

	if (string)
	{
		context->ctx_alias = string;

		// check to make sure the context is not already used at this same
		// query level (if there are no subqueries, this checks that the
		// alias is not used twice in the dsqlScratch).
		for (DsqlContextStack::iterator stack(*dsqlScratch->context); stack.hasData(); ++stack)
		{
			const dsql_ctx* conflict = stack.object();

			if (conflict->ctx_scope_level != context->ctx_scope_level)
				continue;

			const TEXT* conflict_name;
			ISC_STATUS error_code;

			if (conflict->ctx_alias.hasData())
			{
				conflict_name = conflict->ctx_alias.c_str();
				error_code = isc_alias_conflict_err;
				// alias %s conflicts with an alias in the same dsqlScratch.
			}
			else if (conflict->ctx_procedure)
			{
				conflict_name = conflict->ctx_procedure->prc_name.identifier.c_str();
				error_code = isc_procedure_conflict_error;
				// alias %s conflicts with a procedure in the same dsqlScratch.
			}
			else if (conflict->ctx_relation)
			{
				conflict_name = conflict->ctx_relation->rel_name.c_str();
				error_code = isc_relation_conflict_err;
				// alias %s conflicts with a relation in the same dsqlScratch.
			}
			else
				continue;

			if (context->ctx_alias == conflict_name)
			{
				ERRD_post(Arg::Gds(isc_sqlerr) << Arg::Num(-204) <<
						  Arg::Gds(error_code) << Arg::Str(conflict_name));
			}
		}
	}

	if (procedure)
	{
		USHORT count = 0;

		if (procNode->dsqlInputs)
		{
			context->ctx_proc_inputs = PASS1_node_psql(dsqlScratch, procNode->dsqlInputs, false);
			count = context->ctx_proc_inputs->nod_count;
		}

		if (!(dsqlScratch->flags & DsqlCompilerScratch::FLAG_PROCEDURE))
		{
			if (count > procedure->prc_in_count ||
				count < procedure->prc_in_count - procedure->prc_def_count)
			{
				ERRD_post(Arg::Gds(isc_prcmismat) << Arg::Str(procNode->dsqlName.toString()));
			}

			if (count)
			{
				// Initialize this stack variable, and make it look like a node
				AutoPtr<dsql_nod> desc_node(FB_NEW_RPT(*tdbb->getDefaultPool(), 0) dsql_nod);
				dsql_nod* const* input = context->ctx_proc_inputs->nod_arg;

				for (dsql_fld* field = procedure->prc_inputs; *input; ++input, field = field->fld_next)
				{
					DEV_BLKCHK(field, dsql_type_fld);
					DEV_BLKCHK(*input, dsql_type_nod);
					MAKE_desc_from_field(&desc_node->nod_desc, field);
					PASS1_set_parameter_type(dsqlScratch, *input, desc_node, false);
				}
			}
		}
	}

	// push the context onto the dsqlScratch context stack
	// for matching fields against

	dsqlScratch->context->push(context);

	return context;
}


/**

 	PASS1_node

    @brief	Compile a parsed statement into something more interesting.


    @param dsqlScratch
    @param input

 **/
dsql_nod* PASS1_node(DsqlCompilerScratch* dsqlScratch, dsql_nod* input)
{
	thread_db* tdbb = JRD_get_thread_data();

	DEV_BLKCHK(dsqlScratch, dsql_type_req);
	DEV_BLKCHK(input, dsql_type_nod);

	if (!input)
		return NULL;

	dsql_nod* node;
	dsql_nod* sub1;

	// Dispatch on node type.  Fall thru on easy ones

	switch (input->nod_type)
	{
	case nod_class_exprnode:
		{
			ExprNode* exprNode = reinterpret_cast<ExprNode*>(input->nod_arg[0]);
			ProcedureSourceNode* procNode = NULL;
			RelationSourceNode* relNode = NULL;

			//// TODO: Move this to dsqlPass when possible.
			if ((procNode = exprNode->as<ProcedureSourceNode>()) ||
				(relNode = exprNode->as<RelationSourceNode>()))
			{
				bool couldBeCte = true;
				MetaName rel_name;
				string rel_alias;

				if (procNode)
				{
					rel_name = procNode->dsqlName.identifier;
					rel_alias = procNode->alias;
					couldBeCte = !procNode->dsqlInputs && procNode->dsqlName.package.isEmpty();
				}
				else if (relNode)
				{
					rel_name = relNode->dsqlName;
					rel_alias = relNode->alias;
				}

				if (rel_alias.isEmpty())
					rel_alias = rel_name.c_str();

				dsql_nod* cte = couldBeCte ? dsqlScratch->findCTE(rel_name) : NULL;

				if (!cte)
					return pass1_relation(dsqlScratch, input);

				cte->nod_flags |= NOD_SELECT_EXPR_DT_CTE_USED;

				if ((dsqlScratch->flags & DsqlCompilerScratch::FLAG_RECURSIVE_CTE) &&
					 dsqlScratch->currCtes.hasData() &&
					 (dsqlScratch->currCtes.object() == cte))
				{
					ERRD_post(Arg::Gds(isc_sqlerr) << Arg::Num(-104) <<
							  // Recursive CTE member (%s) can refer itself only in FROM clause
							  Arg::Gds(isc_dsql_cte_wrong_reference) << rel_name);
				}

				for (DsqlNodStack::const_iterator stack(dsqlScratch->currCtes); stack.hasData(); ++stack)
				{
					dsql_nod* cte1 = stack.object();
					if (cte1 == cte)
					{
						ERRD_post(Arg::Gds(isc_sqlerr) << Arg::Num(-104) <<
								  // CTE %s has cyclic dependencies
								  Arg::Gds(isc_dsql_cte_cycle) << rel_name);
					}
				}

				dsql_nod* const query = cte->nod_arg[e_sel_query_spec];
				const bool isRecursive =
					(query->nod_type == nod_list) && (query->nod_flags & NOD_UNION_RECURSIVE);

				dsql_str* cte_name = (dsql_str*) cte->nod_arg[e_sel_alias];
				if (!isRecursive)
					cte->nod_arg[e_sel_alias] = (dsql_nod*) MAKE_cstring(rel_alias.c_str());

				dsqlScratch->currCtes.push(cte);

				dsql_nod* derived_node = pass1_derived_table(dsqlScratch,
					cte, (isRecursive ? rel_alias.c_str() : NULL));

				if (!isRecursive)
					cte->nod_arg[e_sel_alias] = (dsql_nod*) cte_name;

				dsqlScratch->currCtes.pop();

				return derived_node;
			}

			node = reinterpret_cast<dsql_nod*>(exprNode->dsqlPass(dsqlScratch));
			if (node != input->nod_arg[0])
			{
				input = MAKE_node(input->nod_type, input->nod_count);
				input->nod_arg[0] = node;
			}
		}
		return input;

	case nod_alias:
		node = MAKE_node(input->nod_type, e_alias_count);
		node->nod_arg[e_alias_value] = sub1 = PASS1_node(dsqlScratch, input->nod_arg[e_alias_value]);
		node->nod_arg[e_alias_alias] = input->nod_arg[e_alias_alias];
		MAKE_desc(dsqlScratch, &sub1->nod_desc, sub1);
		node->nod_desc = sub1->nod_desc;
		return node;

	case nod_collate:
		sub1 = PASS1_node(dsqlScratch, input->nod_arg[e_coll_source]);
		node = pass1_collate(dsqlScratch, sub1, (dsql_str*) input->nod_arg[e_coll_target]);
		return node;

	case nod_delete:
	case nod_insert:
	case nod_merge:
	case nod_update_or_insert:
	case nod_select:
	case nod_with:
		ERRD_post(Arg::Gds(isc_sqlerr) << Arg::Num(-104) <<
				  Arg::Gds(isc_dsql_command_err));

	case nod_select_expr:
		{
			if (input->nod_flags & NOD_SELECT_EXPR_DERIVED)
				return pass1_derived_table(dsqlScratch, input, NULL);

			const DsqlContextStack::iterator base(*dsqlScratch->context);

			dsql_nod* rseNod = PASS1_rse(dsqlScratch, input, NULL);
			RseNode* rse = ExprNode::as<RseNode>(rseNod);

			SubQueryNode* subQueryNode = FB_NEW(*tdbb->getDefaultPool()) SubQueryNode(*tdbb->getDefaultPool(),
				blr_via, rseNod, rse->dsqlSelectList->nod_arg[0], MAKE_node(nod_class_exprnode, 1));
			subQueryNode->dsqlValue2->nod_arg[0] = reinterpret_cast<dsql_nod*>(
				FB_NEW(*tdbb->getDefaultPool()) NullNode(*tdbb->getDefaultPool()));

			node = MAKE_node(nod_class_exprnode, 1);
			node->nod_arg[0] = reinterpret_cast<dsql_nod*>(subQueryNode);

			// Finish off by cleaning up contexts
			dsqlScratch->context->clear(base);

			return node;
		}

	case nod_field_name:
		if (dsqlScratch->isPsql())
			return pass1_variable(dsqlScratch, input);
		return pass1_field(dsqlScratch, input, false, NULL);

	case nod_array:
		if (dsqlScratch->isPsql())
		{
			ERRD_post(Arg::Gds(isc_sqlerr) << Arg::Num(-104) <<
					  Arg::Gds(isc_dsql_invalid_array));
		}
		else
			return pass1_field(dsqlScratch, input, false, NULL);

	case nod_var_name:
		return pass1_variable(dsqlScratch, input);

	// access plan node types

	case nod_plan_item:
		{
			dsql_ctx* context = pass1_alias_list(dsqlScratch, input->nod_arg[0]);
			RecordSourceNode* recSource = NULL;

			if (context->ctx_relation)
			{
				RelationSourceNode* relNode = FB_NEW(*tdbb->getDefaultPool()) RelationSourceNode(
					*tdbb->getDefaultPool());
				relNode->dsqlContext = context;
				recSource = relNode;
			}
			else if (context->ctx_procedure)
			{
				// ASF: Note that usage of procedure name in a PLAN clause causes errors when
				// parsing the BLR.
				ProcedureSourceNode* procNode = FB_NEW(*tdbb->getDefaultPool()) ProcedureSourceNode(
					*tdbb->getDefaultPool());
				procNode->dsqlContext = context;
				recSource = procNode;
			}

			fb_assert(recSource);

			node = MAKE_node(input->nod_type, 2);
			node->nod_arg[0] = sub1 = MAKE_node(nod_class_exprnode, 1);
			sub1->nod_arg[0] = reinterpret_cast<dsql_nod*>(recSource);
			node->nod_arg[1] = PASS1_node(dsqlScratch, input->nod_arg[1]);

			return node;
		}

	case nod_index:
		node = MAKE_node(input->nod_type, 1);
		node->nod_arg[0] = input->nod_arg[0];
		return node;

	case nod_index_order:
		node = MAKE_node(input->nod_type, 2);
		node->nod_arg[0] = input->nod_arg[0];
		node->nod_arg[1] = input->nod_arg[1];
		return node;

	case nod_returning:
		return pass1_returning(dsqlScratch, input);

	default:
		break;
	}

	// Node is simply to be rebuilt -- just recurse merrily

	node = MAKE_node(input->nod_type, input->nod_count);
	const dsql_nod** ptr2 = const_cast<const dsql_nod**>(node->nod_arg);

	dsql_nod** ptr = input->nod_arg;
	for (const dsql_nod* const* const end = ptr + input->nod_count; ptr < end; ptr++)
	{
		DEV_BLKCHK(*ptr, dsql_type_nod);
		*ptr2++ = PASS1_node(dsqlScratch, *ptr);
		DEV_BLKCHK(*(ptr2 - 1), dsql_type_nod);
	}

	// Try to match parameters against things of known data type.
	dsql_nod* sub2 = NULL;

	switch (node->nod_type)
	{
	case nod_assign:
		sub1 = node->nod_arg[0];
		sub2 = node->nod_arg[1];

		// Try to force sub1 to be same type as sub2 eg: ? = FIELD case
		PASS1_set_parameter_type(dsqlScratch, sub1, sub2, false);

		// Try to force sub2 to be same type as sub1 eg: FIELD = ? case
		// Try even when the above call succeeded, because "sub2" may
		// have sub-expressions that should be resolved.
		PASS1_set_parameter_type(dsqlScratch, sub2, sub1, false);

		break;

	default:
		break;
	}

	return node;
}


/**

 	PASS1_rse

    @brief	Compile a record selection expression,
 	bumping up the statement scope level
 	everytime an rse is seen.  The scope
 	level controls parsing of aliases.


    @param dsqlScratch
    @param input
    @param update_lock

 **/
dsql_nod* PASS1_rse(DsqlCompilerScratch* dsqlScratch, dsql_nod* input, dsql_nod* update_lock)
{
	DEV_BLKCHK(dsqlScratch, dsql_type_req);
	DEV_BLKCHK(input, dsql_type_nod);
	DEV_BLKCHK(update_lock, dsql_type_nod);

	fb_assert(input->nod_type == nod_select_expr);

	dsqlScratch->scopeLevel++;
	dsql_nod* node = pass1_rse(dsqlScratch, input, NULL, NULL, update_lock, 0);
	dsqlScratch->scopeLevel--;

	return node;
}


/**

 	PASS1_statement

    @brief	Compile a parsed statement into something more interesting.


    @param dsqlScratch
    @param input

 **/
dsql_nod* PASS1_statement(DsqlCompilerScratch* dsqlScratch, dsql_nod* input)
{
	if (!input)
		return NULL;

	DEV_BLKCHK(dsqlScratch, dsql_type_req);
	DEV_BLKCHK(input, dsql_type_nod);

#ifdef DSQL_DEBUG
	if (DSQL_debug & 2)
	{
		dsql_trace("Node tree at DSQL pass1 entry:");
		DSQL_pretty(input, 0);
	}
#endif

	dsql_nod* node = NULL;
	const DsqlContextStack::iterator base(*dsqlScratch->context);

	// Dispatch on node type.  Fall thru on easy ones

	switch (input->nod_type)
	{
	case nod_def_database:
		dsqlScratch->getStatement()->setType(DsqlCompiledStatement::TYPE_CREATE_DB);
		return input;

	case nod_def_index:
	case nod_mod_index:
	case nod_del_index:
	case nod_def_constraint:
	case nod_grant:
	case nod_revoke:
	case nod_mod_database:
	case nod_del_generator:
	case nod_def_role:
	case nod_del_role:
	case nod_def_filter:
	case nod_del_filter:
	case nod_def_domain:
	case nod_def_udf:
	case nod_del_udf:
	case nod_def_shadow:
	case nod_del_shadow:
	case nod_set_statistics:
	case nod_mod_udf:
	case nod_mod_role:
	case nod_add_user:
	case nod_mod_user:
	case nod_del_user:
		dsqlScratch->getStatement()->setType(DsqlCompiledStatement::TYPE_DDL);
		return input;

	case nod_class_stmtnode:
		node = reinterpret_cast<dsql_nod*>(
			reinterpret_cast<Node*>(input->nod_arg[0])->dsqlPass(dsqlScratch));
		if (node != input->nod_arg[0])
		{
			input = MAKE_node(input->nod_type, input->nod_count);
			input->nod_arg[0] = node;
		}
		return input;

	case nod_assign:
		node = MAKE_node(input->nod_type, input->nod_count);
		node->nod_arg[e_asgn_value] = PASS1_node(dsqlScratch, input->nod_arg[e_asgn_value]);
		node->nod_arg[e_asgn_field] = PASS1_node(dsqlScratch, input->nod_arg[e_asgn_field]);
		break;

	case nod_commit:
		if ((input->nod_arg[e_commit_retain]) &&
			(input->nod_arg[e_commit_retain]->nod_type == nod_retain))
		{
			dsqlScratch->getStatement()->setType(DsqlCompiledStatement::TYPE_COMMIT_RETAIN);
		}
		else
			dsqlScratch->getStatement()->setType(DsqlCompiledStatement::TYPE_COMMIT);
		return input;

	case nod_rollback:
		if ((input->nod_arg[e_rollback_retain]) &&
			(input->nod_arg[e_rollback_retain]->nod_type == nod_retain))
		{
			dsqlScratch->getStatement()->setType(DsqlCompiledStatement::TYPE_ROLLBACK_RETAIN);
		}
		else
			dsqlScratch->getStatement()->setType(DsqlCompiledStatement::TYPE_ROLLBACK);
		return input;

	case nod_delete:
		node = pass1_savepoint(dsqlScratch, pass1_delete(dsqlScratch, input));
		break;

	case nod_get_segment:
	case nod_put_segment:
		pass1_blob(dsqlScratch, input);
		return input;

	case nod_insert:
		node = pass1_savepoint(dsqlScratch, pass1_insert(dsqlScratch, input, false));
		break;

	case nod_merge:
		node = pass1_savepoint(dsqlScratch, pass1_merge(dsqlScratch, input));
		break;

	case nod_block:
		if (input->nod_arg[e_blk_errs])
			dsqlScratch->errorHandlers++;
		else if (input->nod_arg[e_blk_action])
		{
			input->nod_count = 1;
			if (!dsqlScratch->errorHandlers)
				input->nod_type = nod_list;
		}
		else
		{
			input->nod_count = 0;
			input->nod_type = nod_list;
		}

	case nod_list:
		{
			node = MAKE_node(input->nod_type, input->nod_count);
			const dsql_nod** ptr2 = const_cast<const dsql_nod**>(node->nod_arg);
			dsql_nod* const* ptr = input->nod_arg;
			for (const dsql_nod* const* const end = ptr + input->nod_count; ptr < end; ptr++)
			{
				DEV_BLKCHK(*ptr, dsql_type_nod);
				if ((*ptr)->nod_type == nod_assign)
					*ptr2++ = PASS1_node(dsqlScratch, *ptr);
				else
					*ptr2++ = PASS1_statement(dsqlScratch, *ptr);
				DEV_BLKCHK(*(ptr2 - 1), dsql_type_nod);
			}
			if (input->nod_type == nod_block && input->nod_arg[e_blk_errs])
				dsqlScratch->errorHandlers--;
			return node;
		}

	case nod_on_error:
		node = MAKE_node(input->nod_type, input->nod_count);
		node->nod_arg[e_err_errs] = input->nod_arg[e_err_errs];
		node->nod_arg[e_err_action] = PASS1_statement(dsqlScratch, input->nod_arg[e_err_action]);
		return node;

	case nod_select:
		{
			node = PASS1_rse(dsqlScratch, input->nod_arg[e_select_expr], input->nod_arg[e_select_lock]);

			if (input->nod_arg[e_select_update])
			{
				dsqlScratch->getStatement()->setType(DsqlCompiledStatement::TYPE_SELECT_UPD);
				dsqlScratch->getStatement()->addFlags(DsqlCompiledStatement::FLAG_NO_BATCH);
				break;
			}

			// If there is a union without ALL or order by or a select distinct
			// buffering is OK even if stored procedure occurs in the select
			// list. In these cases all of stored procedure is executed under
			// savepoint for open cursor.

			RseNode* rseNode = ExprNode::as<RseNode>(node);

			if (rseNode->dsqlOrder || rseNode->dsqlDistinct)
			{
				dsqlScratch->getStatement()->setFlags(dsqlScratch->getStatement()->getFlags() &
					~DsqlCompiledStatement::FLAG_NO_BATCH);
			}
		}
		break;

	case nod_trans:
		dsqlScratch->getStatement()->setType(DsqlCompiledStatement::TYPE_START_TRANS);
		return input;

	case nod_update:
		node = pass1_savepoint(dsqlScratch, pass1_update(dsqlScratch, input, false));
		break;

	case nod_while:
		{
			node = MAKE_node(input->nod_type, input->nod_count);
			node->nod_arg[e_while_cond] = PASS1_node(dsqlScratch, input->nod_arg[e_while_cond]);

			// CVC: loop numbers should be incremented before analyzing the body
			// to preserve nesting <==> increasing level number
			dsqlScratch->loopLevel++;
			node->nod_arg[e_while_label] = PASS1_label(dsqlScratch, false, input->nod_arg[e_while_label]);
			node->nod_arg[e_while_action] = PASS1_statement(dsqlScratch, input->nod_arg[e_while_action]);
			dsqlScratch->loopLevel--;
			dsqlScratch->labels.pop();
		}
		break;

	case nod_exception:
	case nod_sqlcode:
	case nod_gdscode:
		return input;

	case nod_set_generator:
		node = MAKE_node(input->nod_type, e_gen_id_count);
		node->nod_arg[e_gen_id_value] = PASS1_node(dsqlScratch, input->nod_arg[e_gen_id_value]);
		node->nod_arg[e_gen_id_name] = input->nod_arg[e_gen_id_name];
		dsqlScratch->getStatement()->setType(DsqlCompiledStatement::TYPE_SET_GENERATOR);
		break;

	case nod_set_generator2:
		node = MAKE_node(input->nod_type, e_gen_id_count);
		node->nod_arg[e_gen_id_value] = PASS1_node(dsqlScratch, input->nod_arg[e_gen_id_value]);
		node->nod_arg[e_gen_id_name] = input->nod_arg[e_gen_id_name];
		dsqlScratch->getStatement()->setType(DsqlCompiledStatement::TYPE_SET_GENERATOR);
		break;

	case nod_cursor:
		{
			fb_assert(input->nod_flags > 0);
			// make sure the cursor doesn't exist
			PASS1_cursor_name(dsqlScratch, ((dsql_str*) input->nod_arg[e_cur_name])->str_data,
				NOD_CURSOR_ALL, false);
			// temporarily hide unnecessary contexts and process our RSE
			DsqlContextStack* const base_context = dsqlScratch->context;
			DsqlContextStack temp;
			dsqlScratch->context = &temp;
			const dsql_nod* select = input->nod_arg[e_cur_rse];
			input->nod_arg[e_cur_rse] =
				PASS1_rse(dsqlScratch, select->nod_arg[e_select_expr], select->nod_arg[e_select_lock]);
			dsqlScratch->context->clear();
			dsqlScratch->context = base_context;
			// assign number and store in the dsqlScratch stack
			input->nod_arg[e_cur_number] = (dsql_nod*) (IPTR) dsqlScratch->cursorNumber++;
			dsqlScratch->cursors.push(input);
		}
		return input;

	case nod_src_info:
		{
			input->nod_line = (USHORT) (IPTR) input->nod_arg[e_src_info_line];
			input->nod_column = (USHORT) (IPTR) input->nod_arg[e_src_info_column];
			input->nod_arg[e_src_info_stmt] = PASS1_statement(dsqlScratch, input->nod_arg[e_src_info_stmt]);
			return input;
		}

	case nod_update_or_insert:
		node = pass1_savepoint(dsqlScratch, pass1_update_or_insert(dsqlScratch, input));
		break;

	default:
		ERRD_post(Arg::Gds(isc_sqlerr) << Arg::Num(-901) <<
				  Arg::Gds(isc_dsql_command_err) <<
				  // Unsupported DSQL construct
				  Arg::Gds(isc_dsql_construct_err));
		break;
	}

	// Finish off by cleaning up contexts
	dsqlScratch->context->clear(base);

#ifdef DSQL_DEBUG
	if (DSQL_debug & 1)
	{
		dsql_trace("Node tree at DSQL pass1 exit:");
		DSQL_pretty(node, 0);
	}
#endif

	return node;
}


// Check for ambiguity in a field reference. The list with contexts where the field was found is
// checked and the necessary message is build from it.
void PASS1_ambiguity_check(DsqlCompilerScratch* dsqlScratch,
	const dsql_str* name, const DsqlContextStack& ambiguous_contexts)
{
	// If there are no relations or only 1 there's no ambiguity, thus return.
	if (ambiguous_contexts.getCount() < 2)
		return;

	TEXT buffer[1024];
	USHORT loop = 0;

	buffer[0] = 0;
	TEXT* b = buffer;
	TEXT* p = NULL;

	for (DsqlContextStack::const_iterator stack(ambiguous_contexts); stack.hasData(); ++stack)
	{
		const dsql_ctx* context = stack.object();
		const dsql_rel* relation = context->ctx_relation;
		const dsql_prc* procedure = context->ctx_procedure;
		if (strlen(b) > (sizeof(buffer) - 50))
		{
			// Buffer full
			break;
		}
		// if this is the second loop add "and " before relation.
		if (++loop > 2)
			strcat(buffer, "and ");
		// Process relation when present.
		if (relation)
		{
			if (!(relation->rel_flags & REL_view))
				strcat(buffer, "table ");
			else
				strcat(buffer, "view ");
			strcat(buffer, relation->rel_name.c_str());
		}
		else if (procedure)
		{
			// Process procedure when present.
			strcat(b, "procedure ");
			strcat(b, procedure->prc_name.toString().c_str());
		}
		else
		{
			// When there's no relation and no procedure it's a derived table.
			strcat(b, "derived table ");
			if (context->ctx_alias.hasData())
				strcat(b, context->ctx_alias.c_str());
		}
		strcat(buffer, " ");
		if (!p)
			p = b + strlen(b);
	}

	if (p)
		*--p = 0;

	if (dsqlScratch->clientDialect >= SQL_DIALECT_V6)
	{
		ERRD_post(Arg::Gds(isc_sqlerr) << Arg::Num(-204) <<
				  Arg::Gds(isc_dsql_ambiguous_field_name) << Arg::Str(buffer) << Arg::Str(++p) <<
				  Arg::Gds(isc_random) << Arg::Str(name->str_data));
	}

	ERRD_post_warning(Arg::Warning(isc_sqlwarn) << Arg::Num(204) <<
					  Arg::Warning(isc_dsql_ambiguous_field_name) << Arg::Str(buffer) <<
																	 Arg::Str(++p) <<
					  Arg::Gds(isc_random) << Arg::Str(name->str_data));
}


/**

 	assign_fld_dtype_from_dsc

    @brief	Set a field's descriptor from a DSC
 	(If dsql_fld* is ever redefined this can be removed)


    @param field
    @param nod_desc

 **/
static void assign_fld_dtype_from_dsc( dsql_fld* field, const dsc* nod_desc)
{
	DEV_BLKCHK(field, dsql_type_fld);

	field->fld_dtype = nod_desc->dsc_dtype;
	field->fld_scale = nod_desc->dsc_scale;
	field->fld_sub_type = nod_desc->dsc_sub_type;
	field->fld_length = nod_desc->dsc_length;

	if (nod_desc->dsc_dtype <= dtype_any_text)
	{
		field->fld_collation_id = DSC_GET_COLLATE(nod_desc);
		field->fld_character_set_id = DSC_GET_CHARSET(nod_desc);
	}
	else if (nod_desc->dsc_dtype == dtype_blob)
	{
		field->fld_character_set_id = nod_desc->dsc_scale;
		field->fld_collation_id = nod_desc->dsc_flags >> 8;
	}

	if (nod_desc->dsc_flags & DSC_nullable)
		field->fld_flags |= FLD_nullable;
}


/**
	PASS1_check_unique_fields_names

	check fields (params, variables, cursors etc) names against
	sorted array
	if success, add them into array
 **/
void PASS1_check_unique_fields_names(StrArray& names, const dsql_nod* fields)
{
	if (!fields)
		return;

	const dsql_nod* const* ptr = fields->nod_arg;
	const dsql_nod* const* const end = ptr + fields->nod_count;
	const dsql_fld* field;
	const dsql_str* str;
	const char* name = NULL;

	for (; ptr < end; ptr++)
	{
		switch ((*ptr)->nod_type)
		{
			case nod_def_field:
				field = (dsql_fld*) (*ptr)->nod_arg[e_dfl_field];
				DEV_BLKCHK(field, dsql_type_fld);
				name = field->fld_name.c_str();
				break;

			case nod_cursor:
				str = (dsql_str*) (*ptr)->nod_arg[e_cur_name];
				DEV_BLKCHK(str, dsql_type_str);
				name = str->str_data;
				break;

			default:
				fb_assert(false);
		}

		size_t pos;
		if (!names.find(name, pos))
			names.insert(pos, name);
		else
		{
			ERRD_post(Arg::Gds(isc_sqlerr) << Arg::Num(-637) <<
					  Arg::Gds(isc_dsql_duplicate_spec) << Arg::Str(name));
		}
	}
}


// Compose two booleans.
dsql_nod* PASS1_compose(dsql_nod* expr1, dsql_nod* expr2, UCHAR blrOp)
{
	thread_db* tdbb = JRD_get_thread_data();

	DEV_BLKCHK(expr1, dsql_type_nod);
	DEV_BLKCHK(expr2, dsql_type_nod);

	fb_assert(blrOp == blr_and || blrOp == blr_or);

	if (!expr1)
		return expr2;

	if (!expr2)
		return expr1;

	BinaryBoolNode* binNode = FB_NEW(*tdbb->getDefaultPool()) BinaryBoolNode(
		*tdbb->getDefaultPool(), blrOp, expr1, expr2);

	dsql_nod* node = MAKE_node(nod_class_exprnode, 1);
	node->nod_arg[0] = reinterpret_cast<dsql_nod*>(binNode);

	return node;
}


/**

 	explode_fields

    @brief	Generate a field list that correspond to table fields.


    @param relation

 **/
static dsql_nod* explode_fields(dsql_rel* relation)
{
	DsqlNodStack stack;

	for (dsql_fld* field = relation->rel_fields; field; field = field->fld_next)
	{
		// CVC: Ann Harrison requested to skip COMPUTED fields in INSERT w/o field list.
		if (field->fld_flags & FLD_computed)
		{
			continue;
		}

		stack.push(MAKE_field_name(field->fld_name.c_str()));
	}

	return MAKE_list(stack);
}


/**

 	field_appears_once

    @brief	Check that a field is named only once in INSERT or UPDATE statements.


    @param fields
    @param old_fields
	@param is_insert

 **/
static void field_appears_once(const dsql_nod* fields, const dsql_nod* old_fields,
							   const bool is_insert, const char* dsqlScratch)
{
	for (int i = 0; i < fields->nod_count; ++i)
	{
		const dsql_nod* elem1 = fields->nod_arg[i];
		if (elem1->nod_type == nod_assign && !is_insert)
			elem1 = elem1->nod_arg[e_asgn_field];

		const FieldNode* fieldNode1 = ExprNode::as<FieldNode>(elem1);

		if (fieldNode1)
		{
			const Firebird::MetaName& n1 = fieldNode1->dsqlField->fld_name;

			for (int j = i + 1; j < fields->nod_count; ++j)
			{
				const dsql_nod* elem2 = fields->nod_arg[j];
				if (elem2->nod_type == nod_assign && !is_insert)
					elem2 = elem2->nod_arg[e_asgn_field];

				const FieldNode* fieldNode2 = ExprNode::as<FieldNode>(elem2);

				if (fieldNode2)
				{
					const Firebird::MetaName& n2 = fieldNode2->dsqlField->fld_name;

					if (n1 == n2)
					{
						const dsql_ctx* tmp_ctx = fieldNode2->dsqlContext;
						const dsql_rel* bad_rel = tmp_ctx ? tmp_ctx->ctx_relation : 0;
						field_duplication((bad_rel ? bad_rel->rel_name.c_str() : 0),
							n2.c_str(),
							(is_insert ? old_fields->nod_arg[j] : old_fields->nod_arg[j]->nod_arg[1]),
							dsqlScratch);
					}
				}
			}
		}
	}
}


/**

 	field_duplication

    @brief	Report a field duplication error in INSERT or UPDATE statements.


    @param qualifier_name
    @param field_name
    @param flawed_node
	@param is_insert

 **/
static void field_duplication(const TEXT* qualifier_name, const TEXT* field_name,
	const dsql_nod* flawed_node, const char* dsqlScratch)
{
	TEXT field_buffer[MAX_SQL_IDENTIFIER_SIZE * 2];

	if (qualifier_name)
	{
		sprintf(field_buffer, "%.*s.%.*s", (int) MAX_SQL_IDENTIFIER_LEN, qualifier_name,
				(int) MAX_SQL_IDENTIFIER_LEN, field_name);
		field_name = field_buffer;
	}

	ERRD_post(Arg::Gds(isc_sqlerr) << Arg::Num(-206) <<
			  Arg::Gds(isc_dsql_no_dup_name) << Arg::Str(field_name) << Arg::Str(dsqlScratch) <<
			  Arg::Gds(isc_dsql_line_col_error) << Arg::Num(flawed_node->nod_line) <<
												   Arg::Num(flawed_node->nod_column));
}


// Report a field parsing recognition error.
void PASS1_field_unknown(const TEXT* qualifier_name, const TEXT* field_name,
	const dsql_nod* flawed_node)
{
	TEXT field_buffer[MAX_SQL_IDENTIFIER_SIZE * 2];

	if (qualifier_name)
	{
		sprintf(field_buffer, "%.*s.%.*s", (int) MAX_SQL_IDENTIFIER_LEN, qualifier_name,
				(int) MAX_SQL_IDENTIFIER_LEN, field_name ? field_name : "*");
		field_name = field_buffer;
	}

	if (flawed_node)
	{
		if (field_name)
		{
			ERRD_post(Arg::Gds(isc_sqlerr) << Arg::Num(-206) <<
					  Arg::Gds(isc_dsql_field_err) <<
					  Arg::Gds(isc_random) << Arg::Str(field_name) <<
					  Arg::Gds(isc_dsql_line_col_error) << Arg::Num(flawed_node->nod_line) <<
					  									   Arg::Num(flawed_node->nod_column));
		}
		else
		{
			ERRD_post(Arg::Gds(isc_sqlerr) << Arg::Num(-206) <<
					  Arg::Gds(isc_dsql_field_err) <<
					  Arg::Gds(isc_dsql_line_col_error) << Arg::Num(flawed_node->nod_line) <<
					  									   Arg::Num(flawed_node->nod_column));
		}
	}
	else
	{
		if (field_name)
		{
			ERRD_post(Arg::Gds(isc_sqlerr) << Arg::Num(-206) <<
					  Arg::Gds(isc_dsql_field_err) <<
					  Arg::Gds(isc_random) << Arg::Str(field_name) <<
					  Arg::Gds(isc_dsql_unknown_pos));
		}
		else
		{
			ERRD_post(Arg::Gds(isc_sqlerr) << Arg::Num(-206) <<
					  Arg::Gds(isc_dsql_field_err) <<
					  Arg::Gds(isc_dsql_unknown_pos));
		}
	}
}


/**

 	find_dbkey

    @brief	Find dbkey for named relation in statement's saved dbkeys.


    @param dsqlScratch
    @param relation_name

 **/
static dsql_par* find_dbkey(const dsql_req* request, const dsql_nod* relation_name)
{
	DEV_BLKCHK(request, dsql_type_req);
	DEV_BLKCHK(relation_name, dsql_type_nod);

	const dsql_msg* message = request->getStatement()->getReceiveMsg();
	dsql_par* candidate = NULL;
	const MetaName& relName = ExprNode::as<RelationSourceNode>(relation_name)->dsqlName;

	for (size_t i = 0; i < message->msg_parameters.getCount(); ++i)
	{
		dsql_par* parameter = message->msg_parameters[i];

		if (parameter->par_dbkey_relname.hasData() && parameter->par_dbkey_relname == relName)
		{
			if (candidate)
				return NULL;

			candidate = parameter;
		}
	}

	return candidate;
}


/**

 	find_record_version

    @brief	Find record version for relation in statement's saved record version


    @param dsqlScratch
    @param relation_name

 **/
static dsql_par* find_record_version(const dsql_req* request, const dsql_nod* relation_name)
{
	DEV_BLKCHK(request, dsql_type_req);
	DEV_BLKCHK(relation_name, dsql_type_nod);

	const dsql_msg* message = request->getStatement()->getReceiveMsg();
	dsql_par* candidate = NULL;
	const MetaName& relName = ExprNode::as<RelationSourceNode>(relation_name)->dsqlName;

	for (size_t i = 0; i < message->msg_parameters.getCount(); ++i)
	{
		dsql_par* parameter = message->msg_parameters[i];

		if (parameter->par_rec_version_relname.hasData() &&
			parameter->par_rec_version_relname == relName)
		{
			if (candidate)
				return NULL;

			candidate = parameter;
		}
	}

	return candidate;
}


// Get the context of a relation, procedure or derived table.
static dsql_ctx* get_context(const dsql_nod* node)
{
	const ProcedureSourceNode* procNode;
	const RelationSourceNode* relNode;
	const RseNode* rseNode;

	if ((procNode = ExprNode::as<ProcedureSourceNode>(node)))
		return procNode->dsqlContext;
	else if ((relNode = ExprNode::as<RelationSourceNode>(node)))
		return relNode->dsqlContext;
	else if ((rseNode = ExprNode::as<RseNode>(node)))
		return rseNode->dsqlContext;

	fb_assert(false);
	return NULL;
}


// Get the contexts of a relation, procedure, derived table or a list of joins.
static void get_contexts(DsqlContextStack& contexts, const dsql_nod* node)
{
	const ProcedureSourceNode* procNode;
	const RelationSourceNode* relNode;
	const RseNode* rseNode;

	if ((procNode = ExprNode::as<ProcedureSourceNode>(node)))
		contexts.push(procNode->dsqlContext);
	else if ((relNode = ExprNode::as<RelationSourceNode>(node)))
		contexts.push(relNode->dsqlContext);
	else if ((rseNode = ExprNode::as<RseNode>(node)))
	{
		if (rseNode->dsqlContext)	// derived table
			contexts.push(rseNode->dsqlContext);
		else	// joins
		{
			dsql_nod** ptr = rseNode->dsqlStreams->nod_arg;

			for (const dsql_nod* const* const end = ptr + rseNode->dsqlStreams->nod_count;
				 ptr != end;
				 ++ptr)
			{
				get_contexts(contexts, *ptr);
			}
		}
	}
	else
	{
		fb_assert(false);
	}
}


/**

	PASS1_node_match

    @brief	Compare two nodes for equality of value.

   [2002-08-04]--- Arno Brinkman
 	If ignore_map_cast is true and the node1 is
   type nod_cast or nod_map then PASS1_node_match is
   calling itselfs again with the node1
   CASTs source or map->node.
   This is for allow CAST to other datatypes
   without complaining that it's an unknown
   column reference. (Aggregate functions)


    @param node1
    @param node2
    @param ignore_map_cast

 **/
bool PASS1_node_match(const dsql_nod* node1, const dsql_nod* node2, bool ignore_map_cast)
{
	DEV_BLKCHK(node1, dsql_type_nod);
	DEV_BLKCHK(node2, dsql_type_nod);

	if (!node1 && !node2)
		return true;

	if (!node1 || !node2)
		return false;

	const CastNode* castNode1 = ExprNode::as<CastNode>(node1);

	if (ignore_map_cast && castNode1)
	{
		const CastNode* castNode2 = ExprNode::as<CastNode>(node2);

		// If node2 is also cast and same type continue with both sources.
		if (castNode2 &&
			castNode1->castDesc.dsc_dtype == castNode2->castDesc.dsc_dtype &&
			castNode1->castDesc.dsc_scale == castNode2->castDesc.dsc_scale &&
			castNode1->castDesc.dsc_length == castNode2->castDesc.dsc_length &&
			castNode1->castDesc.dsc_sub_type == castNode2->castDesc.dsc_sub_type)
		{
			return PASS1_node_match(castNode1->dsqlSource, castNode2->dsqlSource, ignore_map_cast);
		}

		return PASS1_node_match(castNode1->dsqlSource, node2, ignore_map_cast);
	}

	const DsqlMapNode* mapNode1 = ExprNode::as<DsqlMapNode>(node1);

	if (ignore_map_cast && mapNode1)
	{
		const DsqlMapNode* mapNode2 = ExprNode::as<DsqlMapNode>(node2);

		if (mapNode2)
		{
			if (mapNode1->context != mapNode2->context)
				return false;

			return PASS1_node_match(mapNode1->map->map_node, mapNode2->map->map_node, ignore_map_cast);
		}

		return PASS1_node_match(mapNode1->map->map_node, node2, ignore_map_cast);
	}

	// We don't care about the alias itself but only about its field.
	if ((node1->nod_type == nod_alias) || (node2->nod_type == nod_alias))
	{
		if ((node1->nod_type == nod_alias) && (node2->nod_type == nod_alias))
		{
			return PASS1_node_match(node1->nod_arg[e_alias_value],
							  node2->nod_arg[e_alias_value], ignore_map_cast);
		}

		if (node1->nod_type == nod_alias) {
			return PASS1_node_match(node1->nod_arg[e_alias_value], node2, ignore_map_cast);
		}
		if (node2->nod_type == nod_alias) {
			return PASS1_node_match(node1, node2->nod_arg[e_alias_value], ignore_map_cast);
		}
	}

	// Handle derived fields.

	const DerivedFieldNode* derivedField1 = ExprNode::as<DerivedFieldNode>(node1);
	const DerivedFieldNode* derivedField2 = ExprNode::as<DerivedFieldNode>(node2);

	if (derivedField1 || derivedField2)
	{
		if (derivedField1 && derivedField2)
		{
			if (derivedField1->scope != derivedField2->scope ||
				derivedField1->name != derivedField2->name)
			{
				return false;
			}

			return PASS1_node_match(derivedField1->dsqlValue, derivedField2->dsqlValue,
				ignore_map_cast);
		}

		if (derivedField1)
			return PASS1_node_match(derivedField1->dsqlValue, node2, ignore_map_cast);

		if (derivedField2)
			return PASS1_node_match(node1, derivedField2->dsqlValue, ignore_map_cast);
	}

	if (node1->nod_type != node2->nod_type || node1->nod_count != node2->nod_count)
		return false;

	// This is to get rid of assertion failures when trying
	// to PASS1_node_match nod_aggregate's children. This was happening because not
	// all of the children are of type "dsql_nod". Pointer to the first child
	// (argument) is actually a pointer to context structure.
	// To compare two nodes of type nod_aggregate we need first to see if they
	// both refer to same context structure. If they do not they are different
	// nodes, if they point to the same context they are the same (because
	// nod_aggregate is created for an rse that have aggregate expression,
	// group by or having clause and each rse has its own context). But just in
	// case we compare two other subtrees.

	switch (node1->nod_type)
	{
		case nod_class_exprnode:
		{
			ExprNode* expr1Node = reinterpret_cast<ExprNode*>(node1->nod_arg[0]);
			ExprNode* expr2Node = reinterpret_cast<ExprNode*>(node2->nod_arg[0]);

			if (expr1Node->type != expr2Node->type)
				return false;

			return expr1Node->dsqlMatch(expr2Node, ignore_map_cast);
		}
	} // switch

	const dsql_nod* const* ptr1 = node1->nod_arg;
	const dsql_nod* const* ptr2 = node2->nod_arg;

	for (const dsql_nod* const* const end = ptr1 + node1->nod_count; ptr1 < end; ptr1++, ptr2++)
	{
		if (!PASS1_node_match(*ptr1, *ptr2, ignore_map_cast))
			return false;
	}

	return true;
}


// Create a compound statement to initialize returning parameters.
static dsql_nod* nullify_returning(DsqlCompilerScratch* dsqlScratch, dsql_nod* input, dsql_nod** list)
{
	thread_db* tdbb = JRD_get_thread_data();

	DEV_BLKCHK(input, dsql_type_nod);

	if (list)
		*list = input;

	dsql_nod* returning = NULL;

	switch (input->nod_type)
	{
		case nod_store:
			returning = input->nod_arg[e_sto_return];
			break;
		case nod_modify:
			returning = input->nod_arg[e_mod_return];
			break;
		case nod_erase:
			returning = input->nod_arg[e_era_return];
			break;
		case nod_modify_current:
			returning = input->nod_arg[e_mdc_return];
			break;
		case nod_erase_current:
			returning = input->nod_arg[e_erc_return];
			break;
		default:
			fb_assert(false);
	}

	if (dsqlScratch->isPsql() || !returning)
		return NULL;

	// If this is a RETURNING in DSQL, we need to initialize the output
	// parameters with NULL, to return in case of empty resultset.
	// Note: this may be changed in the future, i.e. return empty resultset
	// instead of NULLs. In this case, I suppose this function could be
	// completely removed.

	// nod_returning was already processed
	fb_assert(returning->nod_type == nod_list);

	dsql_nod* null_assign = MAKE_node(nod_list, returning->nod_count);

	dsql_nod** ret_ptr = returning->nod_arg;
	dsql_nod** null_ptr = null_assign->nod_arg;
	dsql_nod* temp;

	for (const dsql_nod* const* const end = ret_ptr + returning->nod_count; ret_ptr < end;
		++ret_ptr, ++null_ptr)
	{
		temp = MAKE_node(nod_assign, e_asgn_count);
		temp->nod_arg[e_asgn_value] = MAKE_node(nod_class_exprnode, 1);
		temp->nod_arg[e_asgn_value]->nod_arg[0] = reinterpret_cast<dsql_nod*>(
			FB_NEW(*tdbb->getDefaultPool()) NullNode(*tdbb->getDefaultPool()));

		temp->nod_arg[e_asgn_field] = (*ret_ptr)->nod_arg[1];
		*null_ptr = temp;
	}

	// If asked for, return a compound statement with the initialization and the
	// original statement.
	if (list)
	{
		*list = MAKE_node(nod_list, 2);
		(*list)->nod_arg[0] = null_assign;
		(*list)->nod_arg[1] = input;
	}

	return null_assign;	// return the initialization statement
}


/**

 	pass1_blob

    @brief	Process a blob get or put segment.


    @param dsqlScratch
    @param input

 **/
static void pass1_blob( DsqlCompilerScratch* dsqlScratch, dsql_nod* input)
{
	DEV_BLKCHK(dsqlScratch, dsql_type_req);
	DEV_BLKCHK(input, dsql_type_nod);

	thread_db* tdbb = JRD_get_thread_data();

	PASS1_make_context(dsqlScratch, input->nod_arg[e_blb_relation]);
	FieldNode* field = ExprNode::as<FieldNode>(
		pass1_field(dsqlScratch, input->nod_arg[e_blb_field], false, NULL));

	if (field->dsqlDesc.dsc_dtype != dtype_blob)
	{
		ERRD_post(Arg::Gds(isc_sqlerr) << Arg::Num(-206) <<
				  Arg::Gds(isc_dsql_blob_err));
	}

	dsqlScratch->getStatement()->setType(input->nod_type == nod_get_segment ?
		DsqlCompiledStatement::TYPE_GET_SEGMENT : DsqlCompiledStatement::TYPE_PUT_SEGMENT);

	dsql_blb* blob = FB_NEW(*tdbb->getDefaultPool()) dsql_blb;
	dsqlScratch->getStatement()->setBlob(blob);
	//blob->blb_field = field;
	blob->blb_open_in_msg = dsqlScratch->getStatement()->getSendMsg();
	blob->blb_open_out_msg = FB_NEW(*tdbb->getDefaultPool()) dsql_msg(*tdbb->getDefaultPool());
	blob->blb_segment_msg = dsqlScratch->getStatement()->getReceiveMsg();

	// Create a parameter for the blob segment

	dsql_par* parameter = MAKE_parameter(blob->blb_segment_msg, true, true, 0, NULL);
	blob->blb_segment = parameter;
	parameter->par_desc.dsc_dtype = dtype_text;
	parameter->par_desc.dsc_ttype() = ttype_binary;
	parameter->par_desc.dsc_length = field->dsqlField->fld_seg_length;
	DEV_BLKCHK(field->dsqlField, dsql_type_fld);

	// The Null indicator is used to pass back the segment length,
	// set DSC_nullable so that the SQL_type is set to SQL_TEXT+1 instead
	// of SQL_TEXT.

	if (input->nod_type == nod_get_segment)
		parameter->par_desc.dsc_flags |= DSC_nullable;

	// Create a parameter for the blob id

	dsql_msg* temp_msg = (input->nod_type == nod_get_segment) ?
		blob->blb_open_in_msg : blob->blb_open_out_msg;
	blob->blb_blob_id = parameter = MAKE_parameter(temp_msg, true, true, 0, NULL);
	field->make(dsqlScratch, &parameter->par_desc);
	parameter->par_desc.dsc_dtype = dtype_quad;
	parameter->par_desc.dsc_scale = 0;

	dsql_nod* list = input->nod_arg[e_blb_filter];
	if (list)
	{
		if (list->nod_arg[0]) {
			blob->blb_from = PASS1_node_psql(dsqlScratch, list->nod_arg[0], false);
		}
		if (list->nod_arg[1]) {
			blob->blb_to = PASS1_node_psql(dsqlScratch, list->nod_arg[1], false);
		}
	}
	if (!blob->blb_from) {
		blob->blb_from = MAKE_const_slong(0);
	}
	if (!blob->blb_to) {
		blob->blb_to = MAKE_const_slong(0);
	}

	for (size_t i = 0; i < blob->blb_open_in_msg->msg_parameters.getCount(); ++i)
	{
		dsql_par* parameter = blob->blb_open_in_msg->msg_parameters[i];

		if (parameter->par_index > ((input->nod_type == nod_get_segment) ? 1 : 0))
		{
			parameter->par_desc.dsc_dtype = dtype_short;
			parameter->par_desc.dsc_scale = 0;
			parameter->par_desc.dsc_length = sizeof(SSHORT);
		}
	}
}


/**

 	pass1_collate

    @brief	Turn a collate clause into a cast clause.
 	If the source is not already text, report an error.
 	(SQL 92: Section 13.1, pg 308, item 11)


    @param dsqlScratch
    @param sub1
    @param collation

 **/
static dsql_nod* pass1_collate( DsqlCompilerScratch* dsqlScratch, dsql_nod* sub1,
	const dsql_str* collation)
{
	DEV_BLKCHK(dsqlScratch, dsql_type_req);
	DEV_BLKCHK(sub1, dsql_type_nod);
	DEV_BLKCHK(collation, dsql_type_str);

	thread_db* tdbb = JRD_get_thread_data();

	dsql_fld* field = FB_NEW(*tdbb->getDefaultPool()) dsql_fld(*tdbb->getDefaultPool());
	CastNode* castNode = FB_NEW(*tdbb->getDefaultPool()) CastNode(*tdbb->getDefaultPool(),
		sub1, field);

	MAKE_desc(dsqlScratch, &sub1->nod_desc, sub1);

	dsql_nod* node = MAKE_node(nod_class_exprnode, 1);
	node->nod_arg[0] = reinterpret_cast<dsql_nod*>(castNode);

	if (sub1->nod_desc.dsc_dtype <= dtype_any_text ||
		(sub1->nod_desc.dsc_dtype == dtype_blob && sub1->nod_desc.dsc_sub_type == isc_blob_text))
	{
		assign_fld_dtype_from_dsc(field, &sub1->nod_desc);
		field->fld_character_length = 0;
	}
	else
	{
		ERRD_post(Arg::Gds(isc_sqlerr) << Arg::Num(-204) <<
				  Arg::Gds(isc_dsql_datatype_err) <<
				  Arg::Gds(isc_collation_requires_text));
	}

	DDL_resolve_intl_type(dsqlScratch, field, collation);
	MAKE_desc_from_field(&node->nod_desc, field);

	return node;
}


/**

 	pass1_cursor_context

    @brief	Turn a cursor reference into a record selection expression.


    @param dsqlScratch
    @param cursor
    @param relation_name

 **/
static dsql_ctx* pass1_cursor_context( DsqlCompilerScratch* dsqlScratch, const dsql_nod* cursor,
	const dsql_nod* relation_name)
{
	DEV_BLKCHK(dsqlScratch, dsql_type_req);
	DEV_BLKCHK(cursor, dsql_type_nod);
	DEV_BLKCHK(relation_name, dsql_type_nod);

	const MetaName& relName = ExprNode::as<RelationSourceNode>(relation_name)->dsqlName;

	const dsql_str* string = (dsql_str*) cursor->nod_arg[e_cur_name];
	DEV_BLKCHK(string, dsql_type_str);

	// this function must throw an error if no cursor was found
	const dsql_nod* node = PASS1_cursor_name(dsqlScratch, string->str_data, NOD_CURSOR_ALL, true);
	fb_assert(node);

	const RseNode* rse = ExprNode::as<RseNode>(node->nod_arg[e_cur_rse]);
	fb_assert(rse);

	if (rse->dsqlDistinct)
	{
		// cursor with DISTINCT is not updatable
		ERRD_post(Arg::Gds(isc_sqlerr) << Arg::Num(-510) <<
				  Arg::Gds(isc_dsql_cursor_update_err) << Arg::Str(string->str_data));
	}

	const dsql_nod* temp = rse->dsqlStreams;
	dsql_ctx* context = NULL;

	if (temp->nod_type != nod_class_exprnode)
	{
		dsql_nod* const* ptr = temp->nod_arg;

		for (const dsql_nod* const* const end = ptr + temp->nod_count; ptr != end; ++ptr)
		{
			DEV_BLKCHK(*ptr, dsql_type_nod);
			dsql_nod* r_node = *ptr;
			RelationSourceNode* relNode = ExprNode::as<RelationSourceNode>(r_node);

			if (relNode)
			{
				dsql_ctx* candidate = relNode->dsqlContext;
				DEV_BLKCHK(candidate, dsql_type_ctx);
				const dsql_rel* relation = candidate->ctx_relation;

				if (relation->rel_name == relName)
				{
					if (context)
					{
						ERRD_post(Arg::Gds(isc_sqlerr) << Arg::Num(-504) <<
								  Arg::Gds(isc_dsql_cursor_err) <<
								  Arg::Gds(isc_dsql_cursor_rel_ambiguous) << Arg::Str(relName) <<
								  											 Arg::Str(string->str_data));
					}
					else
						context = candidate;
				}
			}
			else if (ExprNode::as<AggregateSourceNode>(r_node))
			{
				// cursor with aggregation is not updatable
				ERRD_post(Arg::Gds(isc_sqlerr) << Arg::Num(-510) <<
						  Arg::Gds(isc_dsql_cursor_update_err) << Arg::Str(string->str_data));
			}
			// note that UnionSourceNode and joins will cause the error below,
			// as well as derived tables. Some cases deserve fixing in the future
		}
	}

	if (!context)
	{
		ERRD_post(Arg::Gds(isc_sqlerr) << Arg::Num(-504) <<
				  Arg::Gds(isc_dsql_cursor_err) <<
				  Arg::Gds(isc_dsql_cursor_rel_not_found) << Arg::Str(relName) <<
															 Arg::Str(string->str_data));
	}

	return context;
}


/**

 	PASS1_cursor_name

    @brief	Find a cursor.


    @param dsqlScratch
    @param string
	@param mask
	@param existence_flag

 **/
dsql_nod* PASS1_cursor_name(DsqlCompilerScratch* dsqlScratch, const MetaName& string,
	USHORT mask, bool existence_flag)
{
	DEV_BLKCHK(string, dsql_type_str);
	dsql_nod* cursor = NULL;

	if (string.isEmpty())
	{
		if (existence_flag)
		{
			ERRD_post(Arg::Gds(isc_sqlerr) << Arg::Num(-504) <<
					  Arg::Gds(isc_dsql_cursor_err) <<
					  Arg::Gds(isc_dsql_cursor_invalid));
		}
		else
		{
			ERRD_post(Arg::Gds(isc_sqlerr) << Arg::Num(-502) <<
					  Arg::Gds(isc_dsql_decl_err) <<
					  Arg::Gds(isc_dsql_cursor_invalid));
		}
	}

	for (DsqlNodStack::iterator itr(dsqlScratch->cursors); itr.hasData(); ++itr)
	{
		cursor = itr.object();
		const dsql_str* cname = (dsql_str*) cursor->nod_arg[e_cur_name];
		if (strcmp(string.c_str(), cname->str_data) == 0 && (cursor->nod_flags & mask))
			break;
		cursor = NULL;
	}

	if (!cursor && existence_flag)
	{
		ERRD_post(Arg::Gds(isc_sqlerr) << Arg::Num(-504) <<
				  Arg::Gds(isc_dsql_cursor_err) <<
				  Arg::Gds(isc_dsql_cursor_not_found) << Arg::Str(string.c_str()));
	}
	else if (cursor && !existence_flag)
	{
		ERRD_post(Arg::Gds(isc_sqlerr) << Arg::Num(-502) <<
				  Arg::Gds(isc_dsql_decl_err) <<
				  Arg::Gds(isc_dsql_cursor_exists) << Arg::Str(string.c_str()));
	}

	return cursor;
}


/**

 	pass1_cursor_reference

    @brief	Turn a cursor reference into a record selection expression.


    @param dsqlScratch
    @param cursor
    @param relation_name

 **/
static dsql_nod* pass1_cursor_reference( DsqlCompilerScratch* dsqlScratch, const dsql_nod* cursor,
	dsql_nod* relation_name)
{
	DEV_BLKCHK(dsqlScratch, dsql_type_req);
	DEV_BLKCHK(cursor, dsql_type_nod);
	DEV_BLKCHK(relation_name, dsql_type_nod);

	thread_db* tdbb = JRD_get_thread_data();
	MemoryPool& pool = *tdbb->getDefaultPool();

	// Lookup parent dsqlScratch

	const dsql_str* string = (dsql_str*) cursor->nod_arg[e_cur_name];
	DEV_BLKCHK(string, dsql_type_str);

	const dsql_sym* symbol = HSHD_lookup(dsqlScratch->getAttachment(), string->str_data,
		static_cast<SSHORT>(string->str_length), SYM_cursor, 0);

	if (!symbol)
	{
		// cursor is not found
		ERRD_post(Arg::Gds(isc_sqlerr) << Arg::Num(-504) <<
				  Arg::Gds(isc_dsql_cursor_err) <<
				  Arg::Gds(isc_dsql_cursor_not_found) << Arg::Str(string->str_data));
	}

	dsql_req* parent = (dsql_req*) symbol->sym_object;

	// Verify that the cursor is appropriate and updatable

	dsql_par* rv_source = find_record_version(parent, relation_name);

	dsql_par* source;
	if (parent->getStatement()->getType() != DsqlCompiledStatement::TYPE_SELECT_UPD ||
		!(source = find_dbkey(parent, relation_name)) || !rv_source)
	{
		// cursor is not updatable
		ERRD_post(Arg::Gds(isc_sqlerr) << Arg::Num(-510) <<
				  Arg::Gds(isc_dsql_cursor_update_err) << Arg::Str(string->str_data));
	}

	dsqlScratch->getStatement()->setParentRequest(parent);
	dsqlScratch->getStatement()->setParentDbKey(source);
	dsqlScratch->getStatement()->setParentRecVersion(rv_source);
	parent->cursors.add(dsqlScratch->getStatement());

	// Build record selection expression

	RseNode* rse = FB_NEW(pool) RseNode(pool);
	dsql_nod* temp = rse->dsqlStreams = MAKE_node(nod_list, 1);
	dsql_nod* relation_node = pass1_relation(dsqlScratch, relation_name);
	temp->nod_arg[0] = relation_node;

	ComparativeBoolNode* eqlNode = FB_NEW(pool) ComparativeBoolNode(pool,
		blr_eql, MAKE_node(nod_class_exprnode, 1), MAKE_node(nod_class_exprnode, 1));

	dsql_nod* node = MAKE_node(nod_class_exprnode, 1);
	node->nod_arg[0] = reinterpret_cast<dsql_nod*>(eqlNode);

	rse->dsqlWhere = node;

	RecordKeyNode* dbKeyNode = FB_NEW(pool) RecordKeyNode(pool, blr_dbkey);
	dbKeyNode->dsqlRelation = relation_node;
	eqlNode->dsqlArg1->nod_count = 0;
	eqlNode->dsqlArg1->nod_arg[0] = reinterpret_cast<dsql_nod*>(dbKeyNode);

	dsql_par* parameter = MAKE_parameter(dsqlScratch->getStatement()->getSendMsg(),
		false, false, 0, NULL);
	dsqlScratch->getStatement()->setDbKey(parameter);

	ParameterNode* paramNode = FB_NEW(pool) ParameterNode(pool);
	eqlNode->dsqlArg2->nod_count = 0;
	eqlNode->dsqlArg2->nod_arg[0] = reinterpret_cast<dsql_nod*>(paramNode);
	paramNode->dsqlParameterIndex = parameter->par_index;
	paramNode->dsqlParameter = parameter;

	parameter->par_desc = source->par_desc;

	// record version will be set only for V4 - for the parent select cursor
	if (rv_source)
	{
		eqlNode = FB_NEW(pool) ComparativeBoolNode(pool,
			blr_eql, MAKE_node(nod_class_exprnode, 1), MAKE_node(nod_class_exprnode, 1));

		node = MAKE_node(nod_class_exprnode, 1);
		node->nod_arg[0] = reinterpret_cast<dsql_nod*>(eqlNode);

		dbKeyNode = FB_NEW(pool) RecordKeyNode(pool, blr_record_version);
		dbKeyNode->dsqlRelation = relation_node;
		eqlNode->dsqlArg1->nod_count = 0;
		eqlNode->dsqlArg1->nod_arg[0] = reinterpret_cast<dsql_nod*>(dbKeyNode);

		parameter = MAKE_parameter(dsqlScratch->getStatement()->getSendMsg(),
			false, false, 0, NULL);
		dsqlScratch->getStatement()->setRecVersion(parameter);

		paramNode = FB_NEW(pool) ParameterNode(pool);
		eqlNode->dsqlArg2->nod_count = 0;
		eqlNode->dsqlArg2->nod_arg[0] = reinterpret_cast<dsql_nod*>(paramNode);
		paramNode->dsqlParameterIndex = parameter->par_index;
		paramNode->dsqlParameter = parameter;

		parameter->par_desc = rv_source->par_desc;

		rse->dsqlWhere = PASS1_compose(rse->dsqlWhere, node, blr_and);
	}

	dsql_nod* rseNod = MAKE_node(nod_class_exprnode, 1);
	rseNod->nod_arg[0] = reinterpret_cast<dsql_nod*>(rse);

	return rseNod;
}


/**

 	pass1_delete

    @brief	Process DELETE statement.


    @param dsqlScratch
    @param input

 **/
static dsql_nod* pass1_delete( DsqlCompilerScratch* dsqlScratch, dsql_nod* input)
{
	thread_db* tdbb = JRD_get_thread_data();

	DEV_BLKCHK(dsqlScratch, dsql_type_req);
	DEV_BLKCHK(input, dsql_type_nod);

	const dsql_nod* cursor = input->nod_arg[e_del_cursor];
	dsql_nod* relation = input->nod_arg[e_del_relation];
	if (cursor && dsqlScratch->isPsql())
	{
		dsql_nod* anode = MAKE_node(nod_erase_current, e_erc_count);
		anode->nod_arg[e_erc_context] = (dsql_nod*) pass1_cursor_context(dsqlScratch, cursor, relation);
		anode->nod_arg[e_erc_return] = process_returning(dsqlScratch, input->nod_arg[e_del_return]);
		return anode;
	}

	dsqlScratch->getStatement()->setType(
		cursor ? DsqlCompiledStatement::TYPE_DELETE_CURSOR : DsqlCompiledStatement::TYPE_DELETE);
	dsql_nod* node = MAKE_node(nod_erase, e_era_count);

	// Generate record selection expression

	dsql_nod* rseNod;
	if (cursor)
		rseNod = pass1_cursor_reference(dsqlScratch, cursor, relation);
	else
	{
		RseNode* rse = FB_NEW(*tdbb->getDefaultPool()) RseNode(*tdbb->getDefaultPool());

		rseNod = MAKE_node(nod_class_exprnode, 1);
		rseNod->nod_arg[0] = reinterpret_cast<dsql_nod*>(rse);

		dsql_nod* temp = rse->dsqlStreams = MAKE_node(nod_list, 1);
		temp->nod_arg[0] = PASS1_node_psql(dsqlScratch, relation, false);

		if ((temp = input->nod_arg[e_del_boolean]))
			rse->dsqlWhere = PASS1_node_psql(dsqlScratch, temp, false);

		if ((temp = input->nod_arg[e_del_plan]))
			rse->dsqlPlan = PASS1_node_psql(dsqlScratch, temp, false);

		if ((temp = input->nod_arg[e_del_sort]))
			rse->dsqlOrder = pass1_sort(dsqlScratch, temp, NULL);

		if ((temp = input->nod_arg[e_del_rows]))
			pass1_limit(dsqlScratch, temp->nod_arg[e_rows_length], temp->nod_arg[e_rows_skip], rse);

		if (input->nod_arg[e_del_return])
			rseNod->nod_flags |= NOD_SELECT_EXPR_SINGLETON;
	}

	node->nod_arg[e_era_rse] = rseNod;
	node->nod_arg[e_era_relation] = ExprNode::as<RseNode>(rseNod)->dsqlStreams->nod_arg[0];

	node->nod_arg[e_era_return] = process_returning(dsqlScratch, input->nod_arg[e_del_return]);

	nullify_returning(dsqlScratch, node, &node);

	dsqlScratch->context->pop();
	return node;
}


/**

 	process_returning

    @brief	Compile a RETURNING clause (nod_returning or not).


    @param dsqlScratch
    @param input

 **/
static dsql_nod* process_returning(DsqlCompilerScratch* dsqlScratch, dsql_nod* input)
{
	DEV_BLKCHK(dsqlScratch, dsql_type_req);
	DEV_BLKCHK(input, dsql_type_nod);

	dsql_nod* node;

	if (!input || input->nod_type == nod_returning)
		node = PASS1_node(dsqlScratch, input);
	else
		node = PASS1_node_psql(dsqlScratch, input, false);

	if (input && !dsqlScratch->isPsql())
		dsqlScratch->getStatement()->setType(DsqlCompiledStatement::TYPE_EXEC_PROCEDURE);

	return node;
}


// Extract relation and procedure context and expand derived child contexts.
static void pass1_expand_contexts(DsqlContextStack& contexts, dsql_ctx* context)
{
	if (context->ctx_relation || context->ctx_procedure)
	{
		if (context->ctx_parent)
			context = context->ctx_parent;

		contexts.push(context);
	}
	else
	{
		for (DsqlContextStack::iterator i(context->ctx_childs_derived_table); i.hasData(); ++i)
			pass1_expand_contexts(contexts, i.object());
	}
}


/**

 	pass1_derived_table

    @brief	Process derived table which is part of a from clause.


    @param dsqlScratch
    @param input

 **/
static dsql_nod* pass1_derived_table(DsqlCompilerScratch* dsqlScratch, dsql_nod* input,
	const char* cte_alias)
{
	DEV_BLKCHK(dsqlScratch, dsql_type_req);
	DEV_BLKCHK(input, dsql_type_nod);

	thread_db* tdbb = JRD_get_thread_data();
	MemoryPool& pool = *tdbb->getDefaultPool();

	dsql_str* alias = (dsql_str*) input->nod_arg[e_sel_alias];

	// Create the context now, because we need to know it for the tables inside.
	dsql_ctx* const context = PASS1_make_context(dsqlScratch, input);

	// Save some values to restore after rse process.
	DsqlContextStack* const req_base = dsqlScratch->context;
	dsql_str* const aliasRelationPrefix = dsqlScratch->aliasRelationPrefix;

	// Change context, because when we are processing the derived table rse
	// it may not reference to other streams in the same scope_level.
	DsqlContextStack temp;
	// Put special contexts (NEW/OLD) also on the stack
	for (DsqlContextStack::iterator stack(*dsqlScratch->context); stack.hasData(); ++stack)
	{
		dsql_ctx* local_context = stack.object();
		if ((local_context->ctx_scope_level < dsqlScratch->scopeLevel) ||
			(local_context->ctx_flags & CTX_system))
		{
			temp.push(local_context);
		}
	}

	dsql_ctx* baseContext = NULL;

	if (temp.hasData())
		baseContext = temp.object();

	dsqlScratch->context = &temp;
	dsqlScratch->aliasRelationPrefix = pass1_alias_concat(
		aliasRelationPrefix, (alias ? alias->str_data : NULL));

	dsql_nod* query = input->nod_arg[e_sel_query_spec];
	dsql_nod* rse = NULL;
	const bool isRecursive = (query->nod_type == nod_list) && (query->nod_flags & NOD_UNION_RECURSIVE);
	USHORT recursive_map_ctx = 0;

	if (isRecursive)
	{
		// Create dummy, non-recursive select dsqlScratch by doing a union of
		// one, non-recursive member. The dummy will be replaced at the end
		// of this function.

		query->nod_count = 1;
		query->nod_flags &= ~NOD_UNION_RECURSIVE;

		dsql_ctx* baseUnionCtx = dsqlScratch->unionContext.hasData() ?
			dsqlScratch->unionContext.object() : NULL;

		// reserve extra context number for map's secondary context
		recursive_map_ctx = dsqlScratch->contextNumber++;

		dsqlScratch->recursiveCtxId = dsqlScratch->contextNumber;
		rse = pass1_union(dsqlScratch, query, NULL, NULL, NULL, 0);
		dsqlScratch->contextNumber = dsqlScratch->recursiveCtxId + 1;

		// recursive union always have exactly 2 members
		query->nod_count = 2;
		query->nod_flags |= NOD_UNION_RECURSIVE;

		while (dsqlScratch->unionContext.hasData() &&
			   dsqlScratch->unionContext.object() != baseUnionCtx)
		{
			dsqlScratch->unionContext.pop();
		}
	}
	else
	{
		// AB: 2005-01-06
		// If our derived table contains a single query with a sub-select buried
		// inside the select items then we need a special handling, because we don't
		// want creating a new sub-select for every reference outside the derived
		// table to that sub-select.
		// To handle this we simple create a UNION ALL with derived table inside it.
		// Due this mappings are created and we simple reference to these mappings.
		// Optimizer effects:
		//   Good thing is that only 1 recordstream is made for the sub-select, but
		//   the worse thing is that a UNION currently can't be used in
		//   deciding the JOIN order.
		bool foundSubSelect = false;
		RseNode* queryNode = ExprNode::as<RseNode>(query);
		if (queryNode)
			foundSubSelect = SubSelectFinder::find(queryNode->dsqlSelectList);

		int unionContexts = 0;

		if (foundSubSelect)
		{
			DsqlContextStack::const_iterator baseUnion(dsqlScratch->unionContext);

			dsql_nod* union_expr = MAKE_node(nod_list, 1);
			union_expr->nod_arg[0] = input;
			union_expr->nod_flags = NOD_UNION_ALL;
			rse = pass1_union(dsqlScratch, union_expr, NULL, NULL, NULL, 0);

			for (DsqlContextStack::const_iterator i(dsqlScratch->unionContext);
				 i.hasData() && i != baseUnion;
				 ++i)
			{
				temp.push(i.object());
				++unionContexts;
			}
		}
		else
			rse = PASS1_rse(dsqlScratch, input, NULL);

		USHORT minOuterJoin = MAX_USHORT;

		// Finish off by cleaning up contexts and put them into derivedContext
		// so create view (ddl) can deal with it.
		// Also add the used contexts into the childs stack.
		while (temp.hasData() && (temp.object() != baseContext))
		{
			dsql_ctx* childCtx = temp.pop();

			// Do not put the just pushed union contexts in derivedContext. Otherwise duplicate
			// records will appear in RDB$VIEW_RELATIONS.
			if (--unionContexts < 0)
				dsqlScratch->derivedContext.push(childCtx);

			context->ctx_childs_derived_table.push(childCtx);

			// Collect contexts that will be used for blr_derived_expr generation.
			// We want all child contexts with minimum ctx_in_outer_join.
			if (childCtx->ctx_in_outer_join <= minOuterJoin)
			{
				DsqlContextStack contexts;
				pass1_expand_contexts(contexts, childCtx);

				for (DsqlContextStack::iterator i(contexts); i.hasData(); ++i)
				{
					if (i.object()->ctx_in_outer_join < minOuterJoin)
					{
						minOuterJoin = i.object()->ctx_in_outer_join;
						context->ctx_main_derived_contexts.clear();
					}

					context->ctx_main_derived_contexts.push(i.object());
				}
			}
		}

		while (temp.hasData())
			temp.pop();
	}

	context->ctx_rse = rse;

	// CVC: prepare a truncated alias for the derived table here
	// because we need it several times.
	TEXT aliasbuffer[100] = "";
	const TEXT* aliasname = aliasbuffer;
	if (alias)
	{
		int length = alias->str_length;
		if (length > 99)
		{
			length = 99;
			memcpy(aliasbuffer, alias->str_data, length);
			aliasbuffer[length] = 0;
		}
		else
			aliasname = alias->str_data;
	}
	else
		aliasname = "<unnamed>";

	dsql_nod* selectList = ExprNode::as<RseNode>(rse)->dsqlSelectList;

	// If an alias-list is specified, process it.

	const bool ignoreColumnChecks = (input->nod_flags & NOD_SELECT_EXPR_DT_IGNORE_COLUMN_CHECK);

	if (input->nod_arg[e_sel_columns] && input->nod_arg[e_sel_columns]->nod_count)
	{
		dsql_nod* list = input->nod_arg[e_sel_columns];

		// Do both lists have the same number of items?
		if (list->nod_count != selectList->nod_count)
		{
			// Column list by derived table %s [alias-name] has %s [more/fewer] columns
			// than the number of items.

			int errcode = isc_dsql_derived_table_less_columns;
			if (list->nod_count > selectList->nod_count)
				errcode = isc_dsql_derived_table_more_columns;

			ERRD_post(Arg::Gds(isc_sqlerr) << Arg::Num(-104) <<
					  Arg::Gds(isc_dsql_command_err) <<
					  Arg::Gds(errcode) << Arg::Str(aliasname));
		}

		// Generate derived fields and assign alias-name to them.
		for (int count = 0; count < list->nod_count; count++)
		{
			dsql_nod* select_item = selectList->nod_arg[count];
			MAKE_desc(dsqlScratch, &select_item->nod_desc, select_item);

			// Make new derived field node.

			DerivedFieldNode* derivedField = FB_NEW(pool) DerivedFieldNode(pool,
				((dsql_str*) list->nod_arg[count])->str_data, dsqlScratch->scopeLevel, select_item);

			dsql_nod* nod = selectList->nod_arg[count] = MAKE_node(nod_class_exprnode, 1);
			nod->nod_arg[0] = reinterpret_cast<dsql_nod*>(derivedField);
			nod->nod_desc = select_item->nod_desc;
		}
	}
	else
	{
		// For those select-items where no alias is specified try
		// to generate one from the field_name.
		for (int count = 0; count < selectList->nod_count; count++)
		{
			dsql_nod* select_item = pass1_make_derived_field(dsqlScratch, tdbb,
				selectList->nod_arg[count]);

			// Auto-create dummy column name for pass1_any()
			if (ignoreColumnChecks && !ExprNode::is<DerivedFieldNode>(select_item))
			{
				MAKE_desc(dsqlScratch, &select_item->nod_desc, select_item);

				// Construct dummy fieldname
				char fieldname[25];
				sprintf(fieldname, "f%d", count);

				// Make new derived field node.

				DerivedFieldNode* derivedField = FB_NEW(pool) DerivedFieldNode(pool,
					fieldname, dsqlScratch->scopeLevel, select_item);

				dsql_nod* nod = MAKE_node(nod_class_exprnode, 1);
				nod->nod_arg[0] = reinterpret_cast<dsql_nod*>(derivedField);
				nod->nod_desc = select_item->nod_desc;

				select_item = nod;
			}

			selectList->nod_arg[count] = select_item;
		}
	}

	int count;

	// Check if all root select-items have a derived field else show a message.
	for (count = 0; count < selectList->nod_count; count++)
	{
		dsql_nod* select_item = selectList->nod_arg[count];
		DerivedFieldNode* derivedField;

		if ((derivedField = ExprNode::as<DerivedFieldNode>(select_item)))
			derivedField->context = context;
		else
		{
			// no column name specified for column number %d in derived table %s

			ERRD_post(Arg::Gds(isc_sqlerr) << Arg::Num(-104) <<
					  Arg::Gds(isc_dsql_command_err) <<
					  Arg::Gds(isc_dsql_derived_field_unnamed) << Arg::Num(count + 1) <<
																  Arg::Str(aliasname));
		}
	}

	// Check for ambiguous column names inside this derived table.
	for (count = 0; count < selectList->nod_count; ++count)
	{
		const DerivedFieldNode* selectItem1 =
			ExprNode::as<DerivedFieldNode>(selectList->nod_arg[count]);

		for (int count2 = (count + 1); count2 < selectList->nod_count; ++count2)
		{
			const DerivedFieldNode* selectItem2 =
				ExprNode::as<DerivedFieldNode>(selectList->nod_arg[count2]);

			if (selectItem1->name == selectItem2->name)
			{
				// column %s was specified multiple times for derived table %s
				ERRD_post(Arg::Gds(isc_sqlerr) << Arg::Num(-104) <<
						  Arg::Gds(isc_dsql_command_err) <<
						  Arg::Gds(isc_dsql_derived_field_dup_name) << selectItem1->name <<
								aliasname);
			}
		}
	}

	// If we used a dummy rse before, replace it with the real one now.
	// We cannot do this earlier, because recursive processing needs a fully
	// developed context block.
	if (isRecursive)
	{
		dsqlScratch->recursiveCtx = context;
		dsqlScratch->context = &temp;

		dsqlScratch->resetCTEAlias(alias->str_data);

		rse = PASS1_rse(dsqlScratch, input, NULL);

		// Finish off by cleaning up contexts and put them into derivedContext
		// so create view (ddl) can deal with it.
		// Also add the used contexts into the childs stack.
		while (temp.hasData() && (temp.object() != baseContext))
		{
			dsqlScratch->derivedContext.push(temp.object());
			context->ctx_childs_derived_table.push(temp.pop());
		}

		temp.clear();

		ExprNode::as<RseNode>(rse)->dsqlSelectList = ExprNode::as<RseNode>(context->ctx_rse)->dsqlSelectList;

		context->ctx_rse = rse;

		if (cte_alias)
			context->ctx_alias = cte_alias;

		dsqlScratch->context = req_base;

		// Mark union's map context as recursive and assign secondary context number to it.
		dsql_nod* items = ExprNode::as<RseNode>(rse)->dsqlSelectList;
		dsql_nod* map_item = items->nod_arg[0];
		DerivedFieldNode* derivedField;

		if ((derivedField = ExprNode::as<DerivedFieldNode>(map_item)))
			map_item = derivedField->dsqlValue;

		dsql_ctx* map_context = ExprNode::as<DsqlMapNode>(map_item)->context;

		map_context->ctx_flags |= CTX_recursive;
		map_context->ctx_recursive = recursive_map_ctx;
	}

	delete dsqlScratch->aliasRelationPrefix;
	// Restore our original values.
	dsqlScratch->context = req_base;
	dsqlScratch->aliasRelationPrefix = aliasRelationPrefix;

	ExprNode::as<RseNode>(rse)->dsqlContext = context;

	return rse;
}


/**

 	pass1_expand_select_list

    @brief	Expand asterisk nodes into fields.


    @param dsqlScratch
    @param list
    @param streams

 **/
static dsql_nod* pass1_expand_select_list(DsqlCompilerScratch* dsqlScratch, dsql_nod* list,
	dsql_nod* streams)
{
	if (!list)
		list = streams;

	DsqlNodStack stack;
	dsql_nod** ptr = list->nod_arg;

	for (const dsql_nod* const* const end = ptr + list->nod_count; ptr < end; ptr++)
		PASS1_expand_select_node(dsqlScratch, *ptr, stack, true);

	return MAKE_list(stack);
}

// Expand a select item node.
void PASS1_expand_select_node(DsqlCompilerScratch* dsqlScratch, dsql_nod* node, DsqlNodStack& stack,
	bool hide_using)
{
	DEV_BLKCHK(node, dsql_type_nod);

	RseNode* rseNode;
	ProcedureSourceNode* procNode;
	RelationSourceNode* relNode;

	if ((rseNode = ExprNode::as<RseNode>(node)))
	{
		dsql_nod* sub_items = rseNode->dsqlSelectList;

		if (sub_items)	// AB: Derived table support
		{
			dsql_nod** ptr = sub_items->nod_arg;

			for (const dsql_nod* const* const end = ptr + sub_items->nod_count; ptr != end; ++ptr)
			{
				// Create a new alias else mappings would be mangled.
				dsql_nod* select_item = *ptr;

				// select-item should always be a derived field!

				DerivedFieldNode* derivedField;

				if (!(derivedField = ExprNode::as<DerivedFieldNode>(select_item)))
				{
					// Internal dsql error: alias type expected by PASS1_expand_select_node
					ERRD_post(Arg::Gds(isc_sqlerr) << Arg::Num(-104) <<
							  Arg::Gds(isc_dsql_command_err) <<
							  Arg::Gds(isc_dsql_derived_alias_select));
				}

				dsql_ctx* context = derivedField->context;
				DEV_BLKCHK(context, dsql_type_ctx);

				if (!hide_using || context->getImplicitJoinField(derivedField->name, select_item))
					stack.push(select_item);
			}
		}
		else	// joins
		{
			dsql_nod** ptr = rseNode->dsqlStreams->nod_arg;

			for (const dsql_nod* const* const end = ptr + rseNode->dsqlStreams->nod_count;
				 ptr != end;
				 ++ptr)
			{
				PASS1_expand_select_node(dsqlScratch, *ptr, stack, true);
			}
		}
	}
	else if ((procNode = ExprNode::as<ProcedureSourceNode>(node)))
	{
		dsql_ctx* context = procNode->dsqlContext;

		if (context->ctx_procedure)
		{
			for (dsql_fld* field = context->ctx_procedure->prc_outputs; field; field = field->fld_next)
			{
				DEV_BLKCHK(field, dsql_type_fld);

				dsql_nod* select_item = NULL;
				if (!hide_using || context->getImplicitJoinField(field->fld_name, select_item))
				{
					if (!select_item)
						select_item = MAKE_field(context, field, 0);
					stack.push(select_item);
				}
			}
		}
	}
	else if ((relNode = ExprNode::as<RelationSourceNode>(node)))
	{
		dsql_ctx* context = relNode->dsqlContext;

		if (context->ctx_relation)
		{
			for (dsql_fld* field = context->ctx_relation->rel_fields; field; field = field->fld_next)
			{
				DEV_BLKCHK(field, dsql_type_fld);

				dsql_nod* select_item = NULL;
				if (!hide_using || context->getImplicitJoinField(field->fld_name, select_item))
				{
					if (!select_item)
						select_item = MAKE_field(context, field, 0);
					stack.push(select_item);
				}
			}
		}
	}
	else if (node->nod_type == nod_field_name)
	{
		dsql_nod* select_item = pass1_field(dsqlScratch, node, true, NULL);
		// The node could be a relation so call recursively.
		PASS1_expand_select_node(dsqlScratch, select_item, stack, false);
	}
	else
		stack.push(node);
}


/**

 	pass1_field

    @brief	Resolve a field name to an available context.
 	If list is true, then this function can detect and
 	return a relation node if there is no name.   This
 	is used for cases of "SELECT <table_name>. ...".
   CVC: The function attempts to detect
   if an unqualified field appears in more than one context
   and hence it returns the number of occurrences. This was
   added to allow the caller to detect ambiguous commands like
   select  from t1 join t2 on t1.f = t2.f order by common_field.
   While inoffensive on inner joins, it changes the result on outer joins.


    @param dsqlScratch
    @param input
    @param list

 **/
static dsql_nod* pass1_field(DsqlCompilerScratch* dsqlScratch, dsql_nod* input,
							 const bool list, dsql_nod* select_list)
{
	thread_db* tdbb = JRD_get_thread_data();

	DEV_BLKCHK(dsqlScratch, dsql_type_req);
	DEV_BLKCHK(input, dsql_type_nod);

	// handle an array element.
	dsql_nod* indices;
	if (input->nod_type == nod_array)
	{
		indices = input->nod_arg[e_ary_indices];
		input = input->nod_arg[e_ary_array];
	}
	else {
		indices = NULL;
	}

	dsql_str* name;
	const dsql_str* qualifier; // We assume the qualifier was stripped elsewhere.
	if (input->nod_count == 1)
	{
		name = (dsql_str*) input->nod_arg[0];
		qualifier = NULL;
	}
	else
	{
		name = (dsql_str*) input->nod_arg[1];
		qualifier = (dsql_str*) input->nod_arg[0];
	}
	DEV_BLKCHK(name, dsql_type_str);
	DEV_BLKCHK(qualifier, dsql_type_str);

	// CVC: Let's strip trailing blanks or comparisons may fail in dialect 3.
	if (name && name->str_data) {
		fb_utils::exact_name(name->str_data);
	}

    /* CVC: PLEASE READ THIS EXPLANATION IF YOU NEED TO CHANGE THIS CODE.
       You should ensure that this function:
       1.- Never returns NULL. In such case, it such fall back to an invocation
       to PASS1_field_unknown() near the end of this function. None of the multiple callers
       of this function (inside this same module) expect a null pointer, hence they
       will crash the engine in such case.
       2.- Doesn't allocate more than one field in "node". Either you put a break,
       keep the current "continue" or call ALLD_release if you don't want nor the
       continue neither the break if node is already allocated. If it isn't evident,
       but this variable is initialized to zero in the declaration above. You
       may write an explicit line to set it to zero here, before the loop.

       3.- Doesn't waste cycles if qualifier is not null. The problem is not the cycles
       themselves, but the fact that you'll detect an ambiguity that doesn't exist: if
       the field appears in more than one context but it's always qualified, then
       there's no ambiguity. There's PASS1_make_context() that prevents a context's
       alias from being reused. However, other places in the code don't check that you
       don't create a join or subselect with the same context without disambiguating it
       with different aliases. This is the place where resolve_context() is called for
       that purpose. In the future, it will be fine if we force the use of the alias as
       the only allowed qualifier if the alias exists. Hopefully, we will eliminate
       some day this construction: "select table.field from table t" because it
       should be "t.field" instead.

       AB: 2004-01-09
       The explained query directly above doesn't work anymore, thus the day has come ;-)
	   It's allowed to use the same fieldname between different scope levels (sub-queries)
	   without being hit by the ambiguity check. The field uses the first match starting
	   from it's own level (of course ambiguity-check on each level is done).

       4.- Doesn't verify code derived automatically from check constraints. They are
       ill-formed by nature but making that code generation more orthodox is not a
       priority. Typically, they only check a field against a contant. The problem
       appears when they check a field against a subselect, for example. For now,
       allow the user to write ambiguous subselects in check() statements.
       Claudio Valderrama - 2001.1.29.
    */

	if (select_list && !qualifier && name && name->str_data)
	{
		// AB: Check first against the select list for matching column.
		// When no matches at all are found we go on with our
		// normal way of field name lookup.
		dsql_nod* node = PASS1_lookup_alias(dsqlScratch, name, select_list, true);
		if (node)
			return node;
	}

	// Try to resolve field against various contexts;
	// if there is an alias, check only against the first matching

	dsql_nod* node = NULL; // This var must be initialized.
	DsqlContextStack ambiguous_ctx_stack;

	bool resolve_by_alias = true;
	const bool relaxedAliasChecking = Config::getRelaxedAliasChecking();

	while (true)
	{
		// AB: Loop through the scope_levels starting by its own.
		bool done = false;
		USHORT current_scope_level = dsqlScratch->scopeLevel + 1;
		for (; (current_scope_level > 0) && !done; current_scope_level--)
		{

			// If we've found a node we're done.
			if (node)
				break;

			for (DsqlContextStack::iterator stack(*dsqlScratch->context); stack.hasData(); ++stack)
			{
				// resolve_context() checks the type of the
				// given context, so the cast to dsql_ctx* is safe.

				dsql_ctx* context = stack.object();

				if (context->ctx_scope_level != (current_scope_level - 1)) {
					continue;
				}

				dsql_fld* field = resolve_context(dsqlScratch, qualifier, context, resolve_by_alias);

				// AB: When there's no relation and no procedure then we have a derived table.
				const bool is_derived_table =
					(!context->ctx_procedure && !context->ctx_relation && context->ctx_rse);

				if (field)
				{
					// If there's no name then we have most probable an asterisk that
					// needs to be exploded. This should be handled by the caller and
					// when the caller can handle this, list is true.
					if (!name)
					{
						if (list)
						{
							dsql_ctx* stackContext = stack.object();

							RecordSourceNode* recSource = NULL;

							if (context->ctx_relation)
							{
								RelationSourceNode* relNode = FB_NEW(*tdbb->getDefaultPool())
									RelationSourceNode(*tdbb->getDefaultPool());
								relNode->dsqlContext = stackContext;
								recSource = relNode;
							}
							else if (context->ctx_procedure)
							{
								ProcedureSourceNode* procNode = FB_NEW(*tdbb->getDefaultPool())
									ProcedureSourceNode(*tdbb->getDefaultPool());
								procNode->dsqlContext = stackContext;
								recSource = procNode;
							}

							fb_assert(recSource);

							node = MAKE_node(nod_class_exprnode, 1);
							node->nod_arg[0] = reinterpret_cast<dsql_nod*>(recSource);

							return node;
						}

						break;
					}

					dsql_nod* using_field = NULL;

					for (; field; field = field->fld_next)
					{
						if (field->fld_name == name->str_data)
						{
							if (!qualifier)
							{
								if (!context->getImplicitJoinField(field->fld_name, using_field))
								{
									field = NULL;
									break;
								}

								if (using_field)
									field = NULL;
							}

							ambiguous_ctx_stack.push(context);
							break;
						}
					}

					if (qualifier && !field)
					{
						// If a qualifier was present and we don't have found
						// a matching field then we should stop searching.
						// Column unknown error will be raised at bottom of function.
						done = true;
						break;
					}

					if (field || using_field)
					{
						// Intercept any reference to a field with datatype that
						// did not exist prior to V6 and post an error

						if (dsqlScratch->clientDialect <= SQL_DIALECT_V5 && field &&
							(field->fld_dtype == dtype_sql_date ||
								field->fld_dtype == dtype_sql_time || field->fld_dtype == dtype_int64))
						{
								ERRD_post(Arg::Gds(isc_sqlerr) << Arg::Num(-206) <<
										  Arg::Gds(isc_dsql_field_err) <<
										  Arg::Gds(isc_random) << Arg::Str(field->fld_name) <<
										  Arg::Gds(isc_sql_dialect_datatype_unsupport) <<
										  			Arg::Num(dsqlScratch->clientDialect) <<
										  			Arg::Str(DSC_dtype_tostring(static_cast<UCHAR>(field->fld_dtype))));
								return NULL;
						}

						// CVC: Stop here if this is our second or third iteration.
						// Anyway, we can't report more than one ambiguity to the status vector.
						// AB: But only if we're on different scope level, because a
						// node inside the same context should have priority.
						if (node)
							continue;

						if (indices)
							indices = PASS1_node_psql(dsqlScratch, indices, false);

						if (context->ctx_flags & CTX_null)
						{
							node = MAKE_node(nod_class_exprnode, 1);
							node->nod_arg[0] = reinterpret_cast<dsql_nod*>(
								FB_NEW(*tdbb->getDefaultPool()) NullNode(*tdbb->getDefaultPool()));
						}
						else if (field)
							node = MAKE_field(context, field, indices);
						else
							node = list ? using_field : PASS1_node_psql(dsqlScratch, using_field, false);
					}
				}
				else if (is_derived_table)
				{
					// if an qualifier is present check if we have the same derived
					// table else continue;
					if (qualifier)
					{
						if (context->ctx_alias.hasData())
						{
							if (context->ctx_alias != qualifier->str_data)
								continue;
						}
						else
							continue;
					}

					// If there's no name then we have most probable a asterisk that
					// needs to be exploded. This should be handled by the caller and
					// when the caller can handle this, list is true.
					if (!name)
					{
						if (list)
						{
							// Return node which PASS1_expand_select_node() can deal with it.
							return context->ctx_rse;
						}

						break;
					}

					// Because every select item has an alias we can just walk
					// through the list and return the correct node when found.
					const dsql_nod* rse_items = ExprNode::as<RseNode>(context->ctx_rse)->dsqlSelectList;
					dsql_nod* const* ptr = rse_items->nod_arg;

					for (const dsql_nod* const* const end = ptr + rse_items->nod_count;
						 ptr < end; ptr++)
					{
						DerivedFieldNode* selectItem = ExprNode::as<DerivedFieldNode>(*ptr);

						// select-item should always be a alias!
						if (selectItem)
						{
							dsql_nod* using_field = NULL;

							if (!qualifier)
							{
								if (!context->getImplicitJoinField(name->str_data, using_field))
									break;
							}

							if (!strcmp(name->str_data, selectItem->name.c_str()) || using_field)
							{

								// This is a matching item so add the context to the ambiguous list.
								ambiguous_ctx_stack.push(context);

								// Stop here if this is our second or more iteration.
								if (node)
									break;

								node = using_field ? using_field : *ptr;
								break;
							}
						}
						else
						{
							// Internal dsql error: alias type expected by pass1_field
							ERRD_post(Arg::Gds(isc_sqlerr) << Arg::Num(-104) <<
									  Arg::Gds(isc_dsql_command_err) <<
									  Arg::Gds(isc_dsql_derived_alias_field));
						}
					}

					if (!node && qualifier)
					{
						// If a qualifier was present and we don't have found
						// a matching field then we should stop searching.
						// Column unknown error will be raised at bottom of function.
						done = true;
						break;
					}
				}
			}
		}

		if (node)
			break;

		if (resolve_by_alias && !dsqlScratch->checkConstraintTrigger && relaxedAliasChecking)
			resolve_by_alias = false;
		else
			break;
	}

	// CVC: We can't return blindly if this is a check constraint, because there's
	// the possibility of an invalid field that wasn't found. The multiple places that
	// call this function pass1_field() don't expect a NULL pointer, hence will crash.
	// Don't check ambiguity if we don't have a field.

	if (node && name)
		PASS1_ambiguity_check(dsqlScratch, name, ambiguous_ctx_stack);

	// Clean up stack
	ambiguous_ctx_stack.clear();

	if (node)
	{
		return node;
	}

	PASS1_field_unknown((qualifier ? qualifier->str_data : NULL),
		(name ? name->str_data : NULL), input);

	// CVC: PASS1_field_unknown() calls ERRD_post() that never returns, so the next line
	// is only to make the compiler happy.
	return NULL;
}


/**

 	pass1_group_by_list

    @brief	Process GROUP BY list, which may contain
			an ordinal or alias which references the
			select list.

    @param dsqlScratch
    @param input
    @param select_list

 **/
static dsql_nod* pass1_group_by_list(DsqlCompilerScratch* dsqlScratch, dsql_nod* input, dsql_nod* selectList)
{
	DEV_BLKCHK(dsqlScratch, dsql_type_req);
	DEV_BLKCHK(input, dsql_type_nod);
	DEV_BLKCHK(selectList, dsql_type_nod);

	if (input->nod_count > MAX_SORT_ITEMS) // sort, group and distinct have the same limit for now
	{
		// cannot group on more than 255 items
		ERRD_post(Arg::Gds(isc_sqlerr) << Arg::Num(-104) <<
				  Arg::Gds(isc_dsql_command_err) <<
				  Arg::Gds(isc_dsql_max_group_items));
	}

	DsqlNodStack stack;
	dsql_nod** ptr = input->nod_arg;
	for (const dsql_nod* const* const end = ptr + input->nod_count; ptr < end; ptr++)
	{
		DEV_BLKCHK(*ptr, dsql_type_nod);
		dsql_nod* sub = (*ptr);
		dsql_nod* frnode = NULL;
		LiteralNode* literal;

		if (sub->nod_type == nod_field_name)
		{
			// check for alias or field node
			frnode = pass1_field(dsqlScratch, sub, false, selectList);
		}
		else if ((literal = ExprNode::as<LiteralNode>(sub)) && (literal->litDesc.dsc_dtype == dtype_long))
		{
			const ULONG position = literal->getSlong();

			if (position < 1 || !selectList || position > (ULONG) selectList->nod_count)
			{
				// Invalid column position used in the GROUP BY clause
				ERRD_post(Arg::Gds(isc_sqlerr) << Arg::Num(-104) <<
						  Arg::Gds(isc_dsql_column_pos_err) << Arg::Str("GROUP BY"));
			}

			frnode = PASS1_node_psql(dsqlScratch, selectList->nod_arg[position - 1], false);
		}
		else
			frnode = PASS1_node_psql(dsqlScratch, *ptr, false);

		stack.push(frnode);
	}
	// Finally make the complete list.
	dsql_nod* node = MAKE_list(stack);

	return node;
}


// Create (if necessary) a hidden variable to store a temporary value.
static dsql_nod* pass1_hidden_variable(DsqlCompilerScratch* dsqlScratch, dsql_nod* expr)
{
	thread_db* tdbb = JRD_get_thread_data();

	// For some node types, it's better to not create temporary value.
	if (expr->nod_type == nod_class_exprnode)
	{
		switch (ExprNode::fromLegacy(expr)->type)
		{
			case ExprNode::TYPE_CURRENT_DATE:
			case ExprNode::TYPE_CURRENT_TIME:
			case ExprNode::TYPE_CURRENT_TIMESTAMP:
			case ExprNode::TYPE_CURRENT_ROLE:
			case ExprNode::TYPE_CURRENT_USER:
			case ExprNode::TYPE_FIELD:
			case ExprNode::TYPE_INTERNAL_INFO:
			case ExprNode::TYPE_LITERAL:
			case ExprNode::TYPE_NULL:
			case ExprNode::TYPE_PARAMETER:
			case ExprNode::TYPE_RECORD_KEY:
			case ExprNode::TYPE_VARIABLE:
				return NULL;
		}
	}

	VariableNode* varNode = FB_NEW(*tdbb->getDefaultPool()) VariableNode(*tdbb->getDefaultPool());
	varNode->dsqlVar = dsqlScratch->makeVariable(NULL, "", dsql_var::TYPE_HIDDEN,
		0, 0, dsqlScratch->hiddenVarsNumber++);

	dsql_nod* varNod = MAKE_node(nod_class_exprnode, 1);
	varNod->nod_arg[0] = reinterpret_cast<dsql_nod*>(varNode);

	MAKE_desc(dsqlScratch, &varNode->dsqlVar->desc, expr);
	varNod->nod_desc = varNode->dsqlVar->desc;

	return varNod;
}


/**

 	pass1_insert

    @brief	Process INSERT statement.


    @param dsqlScratch
    @param input

 **/
static dsql_nod* pass1_insert( DsqlCompilerScratch* dsqlScratch, dsql_nod* input, bool insert_or_update)
{
	DEV_BLKCHK(dsqlScratch, dsql_type_req);
	DEV_BLKCHK(input, dsql_type_nod);

	dsqlScratch->getStatement()->setType(DsqlCompiledStatement::TYPE_INSERT);
	dsql_nod* node = MAKE_node(nod_store, e_sto_count);

	// Process SELECT expression, if present

	dsql_nod* values;
	dsql_nod* rse = input->nod_arg[e_ins_select];
	if (rse)
	{
		if (input->nod_arg[e_ins_return])
			rse->nod_flags |= NOD_SELECT_EXPR_SINGLETON;

		node->nod_arg[e_sto_rse] = rse = PASS1_rse(dsqlScratch, rse, NULL);
		values = ExprNode::as<RseNode>(rse)->dsqlSelectList;
	}
	else
		values = PASS1_node_psql(dsqlScratch, input->nod_arg[e_ins_values], false);

	// Process relation

	dsql_nod* temp_rel = pass1_relation(dsqlScratch, input->nod_arg[e_ins_relation]);
	node->nod_arg[e_sto_relation] = temp_rel;
	dsql_ctx* context = ExprNode::as<RelationSourceNode>(temp_rel)->dsqlContext;
	DEV_BLKCHK(context, dsql_type_ctx);
	dsql_rel* relation = context->ctx_relation;

	// If there isn't a field list, generate one

	dsql_nod* fields = input->nod_arg[e_ins_fields];
	if (fields)
	{
		const dsql_nod* old_fields = fields; // for error reporting.
		fields = PASS1_node_psql(dsqlScratch, fields, false);
		// We do not allow cases like INSERT INTO T(f1, f2, f1)...
		field_appears_once(fields, old_fields, true, "INSERT");

		// begin IBO hack
		// 02-May-2004, Nickolay Samofatov. Do not constify ptr further e.g. to
		// const dsql_nod* const* .... etc. It chokes GCC 3.4.0
		dsql_nod** ptr = fields->nod_arg;
		for (const dsql_nod* const* const end = ptr + fields->nod_count; ptr < end; ptr++)
		{
			DEV_BLKCHK (*ptr, dsql_type_nod);
			const dsql_nod* temp2 = *ptr;

			const dsql_ctx* tmp_ctx = NULL;
			const TEXT* tmp_name = NULL;
			const FieldNode* fieldNode;
			const DerivedFieldNode* derivedField;

			if ((fieldNode = ExprNode::as<FieldNode>(temp2)))
			{
				tmp_ctx = fieldNode->dsqlContext;
				if (fieldNode->dsqlField)
					tmp_name = fieldNode->dsqlField->fld_name.c_str();
			}
			else if ((derivedField = ExprNode::as<DerivedFieldNode>(temp2)))
			{
				tmp_ctx = derivedField->context;
				tmp_name = derivedField->name.nullStr();
			}

			if (tmp_ctx &&
				((tmp_ctx->ctx_relation && relation->rel_name != tmp_ctx->ctx_relation->rel_name) ||
				 tmp_ctx->ctx_context != context->ctx_context))
			{
				const dsql_rel* bad_rel = tmp_ctx->ctx_relation;
				// At this time, "fields" has been replaced by the processed list in
				// the same variable, so we refer again to input->nod_arg[e_ins_fields].
				// CVC: After three years, made old_fields for that purpose.

				PASS1_field_unknown((bad_rel ? bad_rel->rel_name.c_str() : NULL),
					tmp_name, old_fields->nod_arg[ptr - fields->nod_arg]);
			}
		}
		// end IBO hack
	}
	else
		fields = PASS1_node_psql(dsqlScratch, explode_fields(relation), false);

	// Match field fields and values

	DsqlNodStack stack;

	if (values)
	{
		if (fields->nod_count != values->nod_count)
		{
			// count of column list and value list don't match
			ERRD_post(Arg::Gds(isc_sqlerr) << Arg::Num(-804) <<
					  Arg::Gds(isc_dsql_var_count_err));
		}

		dsql_nod** ptr = fields->nod_arg;
		dsql_nod** ptr2 = values->nod_arg;
		for (const dsql_nod* const* const end = ptr + fields->nod_count; ptr < end; ptr++, ptr2++)
		{
			DEV_BLKCHK(*ptr, dsql_type_nod);
			DEV_BLKCHK(*ptr2, dsql_type_nod);
			dsql_nod* temp = MAKE_node(nod_assign, e_asgn_count);
			temp->nod_arg[e_asgn_value] = *ptr2;
			temp->nod_arg[e_asgn_field] = *ptr;
			stack.push(temp);
			temp = *ptr2;
			PASS1_set_parameter_type(dsqlScratch, temp, *ptr, false);
		}
	}

	node->nod_arg[e_sto_statement] = MAKE_list(stack);

	if (insert_or_update)
	{
		// Clone the insert context, push with name "OLD" in the same scope level and
		// marks it with CTX_null so all fields be resolved to NULL constant.
		dsql_ctx* old_context = FB_NEW(dsqlScratch->getPool()) dsql_ctx(dsqlScratch->getPool());
		*old_context = *context;
		old_context->ctx_alias = old_context->ctx_internal_alias = MAKE_cstring(OLD_CONTEXT)->str_data;
		old_context->ctx_flags |= CTX_system | CTX_null | CTX_returning;
		dsqlScratch->context->push(old_context);

		// clone the insert context and push with name "NEW" in a greater scope level
		dsql_ctx* new_context = FB_NEW(dsqlScratch->getPool()) dsql_ctx(dsqlScratch->getPool());
		*new_context = *context;
		new_context->ctx_scope_level = ++dsqlScratch->scopeLevel;
		new_context->ctx_alias = new_context->ctx_internal_alias = MAKE_cstring(NEW_CONTEXT)->str_data;
		new_context->ctx_flags |= CTX_system | CTX_returning;
		dsqlScratch->context->push(new_context);
	}

	node->nod_arg[e_sto_return] = process_returning(dsqlScratch, input->nod_arg[e_ins_return]);

	if (insert_or_update)
	{
		--dsqlScratch->scopeLevel;
		dsqlScratch->context->pop();
		dsqlScratch->context->pop();
	}

	set_parameters_name(node->nod_arg[e_sto_statement], node->nod_arg[e_sto_relation]);

	if (!insert_or_update)
		nullify_returning(dsqlScratch, node, &node);

	dsqlScratch->context->pop();

	return node;
}


// Process loop interruption.
dsql_nod* PASS1_label(DsqlCompilerScratch* dsqlScratch, bool breakContinue, dsql_nod* label)
{
	DEV_BLKCHK(dsqlScratch, dsql_type_req);
	DEV_BLKCHK(label, dsql_type_nod);

	// look for a label, if specified

	const dsql_str* string = NULL;
	USHORT position = 0;

	if (label)
	{
		fb_assert(label->nod_type == nod_label);
		string = (dsql_str*) label->nod_arg[e_label_name];
		const TEXT* label_string = string->str_data;
		int index = dsqlScratch->loopLevel;
		for (DsqlStrStack::iterator stack(dsqlScratch->labels); stack.hasData(); ++stack)
		{
			const dsql_str* obj = stack.object();
			if (obj)
			{
				const TEXT* obj_string = obj->str_data;
				if (!strcmp(label_string, obj_string))
				{
					position = index;
					break;
				}
			}
			index--;
		}
	}

	USHORT number = 0;

	if (breakContinue)
	{
		if (position > 0)
		{
			// break/continue the specified loop
			number = position;
		}
		else if (label)
		{
			// ERROR: Label %s is not found in the current scope
			ERRD_post(Arg::Gds(isc_sqlerr) << Arg::Num(-104) <<
					  Arg::Gds(isc_dsql_command_err) <<
					  Arg::Gds(isc_dsql_invalid_label) << Arg::Str(string->str_data) <<
														  Arg::Str("is not found"));
		}
		else
		{
			// break/continue the current loop
			number = dsqlScratch->loopLevel;
		}
	}
	else
	{
		if (position > 0)
		{
			// ERROR: Label %s already exists in the current scope
			ERRD_post(Arg::Gds(isc_sqlerr) << Arg::Num(-104) <<
					  Arg::Gds(isc_dsql_command_err) <<
					  Arg::Gds(isc_dsql_invalid_label) << Arg::Str(string->str_data) <<
														  Arg::Str("already exists"));
		}
		else
		{
			// store label name, if specified
			dsqlScratch->labels.push(string);
			number = dsqlScratch->loopLevel;
		}
	}

	fb_assert(number > 0 && number <= dsqlScratch->loopLevel);

	if (!label)
	{
		label = MAKE_node(nod_label, e_label_count);
		// this label is unnamed, i.e. its nod_arg[e_label_name] is NULL
	}

	label->nod_arg[e_label_number] = (dsql_nod*) (IPTR) number;

	return label;
}


/**

 	pass1_limit

    @brief	Process the limit clause (FIRST/SKIP/ROWS)

    @param dsqlScratch
    @param firstNode
    @param skipNode
	@param rse

 **/
static void pass1_limit(DsqlCompilerScratch* dsqlScratch,
						dsql_nod* firstNode, dsql_nod* skipNode,
						RseNode* rse)
{
	DEV_BLKCHK(dsqlScratch, dsql_type_req);
	DEV_BLKCHK(firstNode, dsql_type_nod);
	DEV_BLKCHK(skipNode, dsql_type_nod);

	// Initialize this stack variable, and make it look like a node
	AutoPtr<dsql_nod> descNode(FB_NEW_RPT(*getDefaultMemoryPool(), 0) dsql_nod);

	if (dsqlScratch->clientDialect <= SQL_DIALECT_V5)
		descNode->nod_desc.makeLong(0);
	else
		descNode->nod_desc.makeInt64(0);

	rse->dsqlFirst = PASS1_node_psql(dsqlScratch, firstNode, false);
	PASS1_set_parameter_type(dsqlScratch, rse->dsqlFirst, descNode, false);

	rse->dsqlSkip = PASS1_node_psql(dsqlScratch, skipNode, false);
	PASS1_set_parameter_type(dsqlScratch, rse->dsqlSkip, descNode, false);
}


// Lookup a matching item in the select list. Return node if found else return NULL.
// If more matches are found we raise ambiguity error.
dsql_nod* PASS1_lookup_alias(DsqlCompilerScratch* dsqlScratch, const dsql_str* name,
	dsql_nod* selectList, bool process)
{
	dsql_nod* returnNode = NULL;
	dsql_nod** ptr = selectList->nod_arg;
	const dsql_nod* const* const end = ptr + selectList->nod_count;
	for (; ptr < end; ptr++)
	{
		dsql_nod* matchingNode = NULL;
		dsql_nod* node = *ptr;
		FieldNode* fieldNode;
		DerivedFieldNode* derivedField;

		switch (node->nod_type)
		{
			case nod_alias:
				{
					const dsql_str* alias = (dsql_str*) node->nod_arg[e_alias_alias];
					if (!strcmp(alias->str_data, name->str_data)) {
						matchingNode = node;
					}
				}
				break;

			default:
				if ((fieldNode = ExprNode::as<FieldNode>(node)))
				{
					if (fieldNode->dsqlField->fld_name == name->str_data)
						matchingNode = node;
				}
				else if ((derivedField = ExprNode::as<DerivedFieldNode>(node)))
				{
					if (strcmp(derivedField->name.c_str(), name->str_data) == 0)
						matchingNode = node;
				}
				break;
		}

		if (matchingNode)
		{
			if (process)
				matchingNode = PASS1_node_psql(dsqlScratch, matchingNode, false);

			if (returnNode)
			{
				// There was already a node matched, thus raise ambiguous field name error.
				TEXT buffer1[256];
				buffer1[0] = 0;
				switch (returnNode->nod_type)
				{
					case nod_alias:
						strcat(buffer1, "an alias");
						break;

					default:
						if (ExprNode::is<FieldNode>(returnNode))
							strcat(buffer1, "a field");
						else if (ExprNode::is<DerivedFieldNode>(returnNode))
							strcat(buffer1, "a derived field");
						else
							strcat(buffer1, "an item");
						break;
				}

				TEXT buffer2[256];
				buffer2[0] = 0;

				switch (matchingNode->nod_type)
				{
					case nod_alias:
						strcat(buffer2, "an alias");
						break;

					default:
						if (ExprNode::is<FieldNode>(matchingNode))
							strcat(buffer2, "a field");
						else if (ExprNode::is<DerivedFieldNode>(matchingNode))
							strcat(buffer2, "a derived field");
						else
							strcat(buffer2, "an item");
						break;
				}

				strcat(buffer2, " in the select list with name");

				ERRD_post(Arg::Gds(isc_sqlerr) << Arg::Num(-204) <<
						  Arg::Gds(isc_dsql_ambiguous_field_name) << Arg::Str(buffer1) <<
																	 Arg::Str(buffer2) <<
						  Arg::Gds(isc_random) << Arg::Str(name->str_data));
			}

			returnNode = matchingNode;
		}
	}

	return returnNode;
}

/**

 	pass1_make_derived_field

    @brief	Create a derived field based on underlying expressions


    @param dsqlScratch
    @param tdbb
    @param select_item

 **/
static dsql_nod* pass1_make_derived_field(DsqlCompilerScratch* dsqlScratch, thread_db* tdbb,
	dsql_nod* select_item)
{
	DEV_BLKCHK(select_item, dsql_type_nod);

	MemoryPool& pool = *tdbb->getDefaultPool();

	switch (select_item->nod_type)
	{
		case nod_alias:
			{
				const dsql_str* alias_alias = (dsql_str*) select_item->nod_arg[e_alias_alias];

				// Create a derived field and ignore alias node.

				DerivedFieldNode* newField = FB_NEW(pool) DerivedFieldNode(pool,
					alias_alias->str_data, dsqlScratch->scopeLevel, select_item->nod_arg[e_alias_value]);

				dsql_nod* nod = MAKE_node(nod_class_exprnode, 1);
				nod->nod_arg[0] = reinterpret_cast<dsql_nod*>(newField);
				nod->nod_desc = select_item->nod_desc;

				return nod;
			}

		case nod_class_exprnode:
			{
				SubQueryNode* subQueryNode;
				DsqlMapNode* mapNode;
				FieldNode* fieldNode;
				DerivedFieldNode* derivedField;

				if ((subQueryNode = ExprNode::as<SubQueryNode>(select_item)))
				{
					// Try to generate derived field from sub-select
					dsql_nod* derived_field = pass1_make_derived_field(dsqlScratch, tdbb,
						subQueryNode->dsqlValue1);

					if ((derivedField = ExprNode::as<DerivedFieldNode>(derived_field)))
					{
						derivedField->dsqlValue = select_item;
						return derived_field;
					}
				}
				else if ((mapNode = ExprNode::as<DsqlMapNode>(select_item)))
				{
					// Aggregate's have map on top.
					dsql_nod* derived_field = pass1_make_derived_field(dsqlScratch, tdbb, mapNode->map->map_node);

					// If we had succesfully made a derived field node change it with orginal map.
					if ((derivedField = ExprNode::as<DerivedFieldNode>(derived_field)))
					{
						derivedField->dsqlValue = select_item;
						derivedField->scope = dsqlScratch->scopeLevel;
						derived_field->nod_desc = select_item->nod_desc;
						return derived_field;
					}
				}
				else if ((fieldNode = ExprNode::as<FieldNode>(select_item)))
				{
					// Create a derived field and hook in.

					DerivedFieldNode* newField = FB_NEW(pool) DerivedFieldNode(pool,
						fieldNode->dsqlField->fld_name, dsqlScratch->scopeLevel, select_item);

					dsql_nod* nod = MAKE_node(nod_class_exprnode, 1);
					nod->nod_arg[0] = reinterpret_cast<dsql_nod*>(newField);
					nod->nod_desc = fieldNode->dsqlDesc;

					return nod;
				}
				else if ((derivedField = ExprNode::as<DerivedFieldNode>(select_item)))
				{
					// Create a derived field that points to a derived field.

					DerivedFieldNode* newField = FB_NEW(pool) DerivedFieldNode(pool,
						derivedField->name, dsqlScratch->scopeLevel, select_item);

					dsql_nod* nod = MAKE_node(nod_class_exprnode, 1);
					nod->nod_arg[0] = reinterpret_cast<dsql_nod*>(newField);
					nod->nod_desc = select_item->nod_desc;

					return nod;
				}

				break;
			}

		default:
			break;
	}

	return select_item;
}


/**
 	pass1_merge

    @brief	Process MERGE statement.


    @param dsqlScratch
    @param input

 **/
static dsql_nod* pass1_merge(DsqlCompilerScratch* dsqlScratch, dsql_nod* input)
{
	// Puts a blr_send before blr_for in DSQL statements.
	class MergeSendNode : public TypedNode<DsqlOnlyStmtNode, StmtNode::TYPE_MERGE>
	{
	public:
		explicit MergeSendNode(MemoryPool& pool, dsql_nod* aStmt)
			: TypedNode<DsqlOnlyStmtNode, StmtNode::TYPE_MERGE>(pool),
			  stmt(aStmt)
		{
		}

	public:
		virtual void print(string& text, Array<dsql_nod*>& nodes) const
		{
			text = "MergeSendNode";
			nodes.add(stmt);
		}

		// Do not make dsqlPass to process 'stmt'. It's already processed.

		virtual void genBlr(DsqlCompilerScratch* dsqlScratch)
		{
			dsql_msg* message = dsqlScratch->getStatement()->getReceiveMsg();

			if (!dsqlScratch->isPsql() && message)
			{
				dsqlScratch->appendUChar(blr_send);
				dsqlScratch->appendUChar(message->msg_number);
			}

			GEN_statement(dsqlScratch, stmt);
		}

	private:
		dsql_nod* stmt;
	};

	DEV_BLKCHK(dsqlScratch, dsql_type_req);
	DEV_BLKCHK(input, dsql_type_nod);

	thread_db* tdbb = JRD_get_thread_data();
	MemoryPool& pool = *tdbb->getDefaultPool();

	dsql_nod* source = input->nod_arg[e_mrg_using];		// USING
	dsql_nod* target = input->nod_arg[e_mrg_relation];	// INTO

	fb_assert(input->nod_arg[e_mrg_when]->nod_type == nod_merge_when);
	dsql_nod* whenNode = input->nod_arg[e_mrg_when]->nod_arg[e_mrg_when_matched];

	dsql_nod* updDelCondition = NULL;
	if (whenNode)
	{
		if (whenNode->nod_type == nod_merge_update)
			updDelCondition = whenNode->nod_arg[e_mrg_update_condition];
		else if (whenNode->nod_type == nod_merge_delete)
			updDelCondition = whenNode->nod_arg[e_mrg_delete_condition];
	}

	dsql_nod* insCondition = input->nod_arg[e_mrg_when]->nod_arg[e_mrg_when_not_matched] ?
		input->nod_arg[e_mrg_when]->nod_arg[e_mrg_when_not_matched]->nod_arg[e_mrg_insert_condition] :
		NULL;

	// Build a join between USING and INTO tables.
	RseNode* join = FB_NEW(pool) RseNode(pool);
	join->dsqlExplicitJoin = true;
	join->dsqlFrom = MAKE_node(nod_list, 2);

	join->dsqlFrom->nod_arg[0] = source;

	// Left join if WHEN NOT MATCHED is present.
	if (input->nod_arg[e_mrg_when]->nod_arg[e_mrg_when_not_matched])
		join->rse_jointype = blr_left;

	join->dsqlFrom->nod_arg[1] = target;
	join->dsqlWhere = input->nod_arg[e_mrg_condition];

	RseNode* querySpec = FB_NEW(pool) RseNode(pool);
	querySpec->dsqlFrom = MAKE_node(nod_list, 1);
	querySpec->dsqlFrom->nod_arg[0] = MAKE_node(nod_class_exprnode, 1);
	querySpec->dsqlFrom->nod_arg[0]->nod_arg[0] = reinterpret_cast<dsql_nod*>(join);

	dsql_nod* querySpecNod = MAKE_node(nod_class_exprnode, 1);
	querySpecNod->nod_arg[0] = reinterpret_cast<dsql_nod*>(querySpec);

	if (updDelCondition || insCondition)
	{
		const char* targetName = ExprNode::as<RelationSourceNode>(target)->alias.nullStr();
		if (!targetName)
			targetName = ExprNode::as<RelationSourceNode>(target)->dsqlName.c_str();

		if (whenNode)	// WHEN MATCHED
		{
			MissingBoolNode* missingNode = FB_NEW(pool) MissingBoolNode(
				pool, MAKE_node(nod_class_exprnode, 1));
			missingNode->dsqlArg->nod_arg[0] = reinterpret_cast<dsql_nod*>(
				FB_NEW(pool) RecordKeyNode(pool, blr_dbkey, targetName));

			NotBoolNode* notNode = FB_NEW(pool) NotBoolNode(
				pool, MAKE_node(nod_class_exprnode, 1));
			notNode->dsqlArg->nod_arg[0] = reinterpret_cast<dsql_nod*>(missingNode);

			querySpec->dsqlWhere = MAKE_node(nod_class_exprnode, 1);
			querySpec->dsqlWhere->nod_arg[0] = reinterpret_cast<dsql_nod*>(notNode);
		}

		if (updDelCondition)
			querySpec->dsqlWhere = PASS1_compose(querySpec->dsqlWhere, updDelCondition, blr_and);

		dsql_nod* temp = NULL;

		if (input->nod_arg[e_mrg_when]->nod_arg[e_mrg_when_not_matched])	// WHEN NOT MATCHED
		{
			MissingBoolNode* missingNode = FB_NEW(pool) MissingBoolNode(
				pool, MAKE_node(nod_class_exprnode, 1));
			missingNode->dsqlArg->nod_arg[0] = reinterpret_cast<dsql_nod*>(
				FB_NEW(pool) RecordKeyNode(pool, blr_dbkey, targetName));

			temp = MAKE_node(nod_class_exprnode, 1);
			temp->nod_arg[0] = reinterpret_cast<dsql_nod*>(missingNode);

			if (insCondition)
				temp = PASS1_compose(temp, insCondition, blr_and);

			querySpec->dsqlWhere = PASS1_compose(querySpec->dsqlWhere, temp, blr_or);
		}
	}

	dsql_nod* select_expr = MAKE_node(nod_select_expr, e_sel_count);
	select_expr->nod_arg[e_sel_query_spec] = querySpecNod;

	dsql_nod* select = MAKE_node(nod_select, e_select_count);
	select->nod_arg[e_select_expr] = select_expr;

	// build a FOR SELECT node
	ForNode* forNode = FB_NEW(pool) ForNode(pool);
	forNode->dsqlSelect = select;
	forNode->dsqlAction = MAKE_node(nod_list, 0);

	dsql_nod* for_select = MAKE_node(nod_class_stmtnode, 1);
	for_select->nod_arg[0] = (dsql_nod*) forNode;
	for_select = PASS1_statement(dsqlScratch, for_select);
	forNode = (ForNode*) for_select->nod_arg[0];

	if (input->nod_arg[e_mrg_return])
		forNode->dsqlForceSingular = true;

	// Get the already processed relations.
	source = ExprNode::as<RseNode>(ExprNode::as<RseNode>(
		forNode->dsqlSelect)->dsqlStreams->nod_arg[0])->dsqlStreams->nod_arg[0];
	target = ExprNode::as<RseNode>(ExprNode::as<RseNode>(
		forNode->dsqlSelect)->dsqlStreams->nod_arg[0])->dsqlStreams->nod_arg[1];

	DsqlContextStack usingCtxs;
	get_contexts(usingCtxs, source);

	dsql_nod* update = NULL;
	dsql_nod* matchedRet = NULL;
	dsql_nod* nullRet = NULL;

	if (whenNode && whenNode->nod_type == nod_merge_update)
	{
		// get the assignments of the UPDATE dsqlScratch
		dsql_nod* list = whenNode->nod_arg[e_mrg_update_statement];
		fb_assert(list->nod_type == nod_list);

		Array<dsql_nod*> org_values, new_values;

		// separate the new and org values to process in correct contexts
		for (int i = 0; i < list->nod_count; ++i)
		{
			const dsql_nod* const assign = list->nod_arg[i];
			fb_assert(assign->nod_type == nod_assign);
			org_values.add(assign->nod_arg[e_asgn_value]);
			new_values.add(assign->nod_arg[e_asgn_field]);
		}

		// build the MODIFY node
		update = MAKE_node(nod_modify_current, e_mdc_count);
		dsql_ctx* old_context = get_context(target);
		dsql_nod** ptr;

		update->nod_arg[e_mdc_context] = (dsql_nod*) old_context;

		dsqlScratch->scopeLevel++;	// go to the same level of source and target contexts

		for (DsqlContextStack::iterator itr(usingCtxs); itr.hasData(); ++itr)
			dsqlScratch->context->push(itr.object());	// push the USING contexts

		dsqlScratch->context->push(old_context);	// process old context values

		for (ptr = org_values.begin(); ptr < org_values.end(); ++ptr)
			*ptr = PASS1_node_psql(dsqlScratch, *ptr, false);

		// and pop the contexts
		dsqlScratch->context->pop();
		dsqlScratch->context->pop();
		dsqlScratch->scopeLevel--;

		// process relation
		update->nod_arg[e_mdc_update] = pass1_relation(dsqlScratch, input->nod_arg[e_mrg_relation]);
		dsql_ctx* mod_context = get_context(update->nod_arg[e_mdc_update]);

		// process new context values
		for (ptr = new_values.begin(); ptr < new_values.end(); ++ptr)
			*ptr = PASS1_node_psql(dsqlScratch, *ptr, false);

		dsqlScratch->context->pop();

		if (input->nod_arg[e_mrg_return])
		{
			// Repush the source contexts.
			dsqlScratch->scopeLevel++;	// go to the same level of source and target contexts

			for (DsqlContextStack::iterator itr(usingCtxs); itr.hasData(); ++itr)
				dsqlScratch->context->push(itr.object());	// push the USING contexts

			dsqlScratch->context->push(old_context);	// process old context values

			mod_context->ctx_scope_level = old_context->ctx_scope_level;

			matchedRet = update->nod_arg[e_mdc_return] = ReturningProcessor(
				dsqlScratch, old_context, mod_context).process(input->nod_arg[e_mrg_return]);

			nullRet = nullify_returning(dsqlScratch, update);

			// And pop them.
			dsqlScratch->context->pop();
			dsqlScratch->context->pop();
			dsqlScratch->scopeLevel--;
		}

		// recreate list of assignments
		update->nod_arg[e_mdc_statement] = list = MAKE_node(nod_list, list->nod_count);

		for (int i = 0; i < list->nod_count; ++i)
		{
			if (!PASS1_set_parameter_type(dsqlScratch, org_values[i], new_values[i], false))
				PASS1_set_parameter_type(dsqlScratch, new_values[i], org_values[i], false);

			dsql_nod* assign = MAKE_node(nod_assign, e_asgn_count);
			assign->nod_arg[e_asgn_value] = org_values[i];
			assign->nod_arg[e_asgn_field] = new_values[i];
			list->nod_arg[i] = assign;
		}

		// We do not allow cases like UPDATE SET f1 = v1, f2 = v2, f1 = v3...
		field_appears_once(update->nod_arg[e_mdc_statement],
			whenNode->nod_arg[e_mrg_update_statement], false, "MERGE");
	}
	else if (whenNode && whenNode->nod_type == nod_merge_delete)
	{
		// build the DELETE node
		update = MAKE_node(nod_erase_current, e_erc_count);
		dsql_ctx* context = get_context(target);
		update->nod_arg[e_erc_context] = (dsql_nod*) context;

		if (input->nod_arg[e_mrg_return])
		{
			dsqlScratch->scopeLevel++;	// go to the same level of source and target contexts

			for (DsqlContextStack::iterator itr(usingCtxs); itr.hasData(); ++itr)
				dsqlScratch->context->push(itr.object());	// push the USING contexts

			dsqlScratch->context->push(context);	// process old context values

			matchedRet = update->nod_arg[e_erc_return] = ReturningProcessor(
				dsqlScratch, context, NULL).process(input->nod_arg[e_mrg_return]);

			nullRet = nullify_returning(dsqlScratch, update);

			// and pop the contexts
			dsqlScratch->context->pop();
			dsqlScratch->context->pop();
			dsqlScratch->scopeLevel--;
		}
	}

	whenNode = input->nod_arg[e_mrg_when]->nod_arg[e_mrg_when_not_matched];
	dsql_nod* insert = NULL;

	if (whenNode)
	{
		dsqlScratch->scopeLevel++;	// go to the same level of the source context

		for (DsqlContextStack::iterator itr(usingCtxs); itr.hasData(); ++itr)
			dsqlScratch->context->push(itr.object());	// push the USING contexts

		// the INSERT relation should be processed in a higher level than the source context
		dsqlScratch->scopeLevel++;

		// build the INSERT node
		insert = MAKE_node(nod_insert, e_ins_count);
		insert->nod_arg[e_ins_relation] = input->nod_arg[e_mrg_relation];
		insert->nod_arg[e_ins_fields] = whenNode->nod_arg[e_mrg_insert_fields];
		insert->nod_arg[e_ins_values] = whenNode->nod_arg[e_mrg_insert_values];

		insert = pass1_insert(dsqlScratch, insert, false);

		// restore the scope level
		dsqlScratch->scopeLevel--;

		dsql_nod* insRet = ReturningProcessor::clone(input->nod_arg[e_mrg_return], matchedRet);

		if (insRet)
		{
			dsql_ctx* old_context = get_context(target);
			dsqlScratch->context->push(old_context);

			dsql_ctx* context = get_context(insert->nod_arg[e_sto_relation]);
			context->ctx_scope_level = old_context->ctx_scope_level;

			insert->nod_arg[e_sto_return] = ReturningProcessor(
				dsqlScratch, old_context, context).process(insRet);

			if (!matchedRet)
				nullRet = nullify_returning(dsqlScratch, insert);

			dsqlScratch->context->pop();
		}

		// pop the USING context
		dsqlScratch->context->pop();
		dsqlScratch->scopeLevel--;
	}

	MissingBoolNode* missingNode = FB_NEW(pool) MissingBoolNode(
		pool, MAKE_node(nod_class_exprnode, 1));

	RecordKeyNode* dbKeyNode = FB_NEW(pool) RecordKeyNode(pool, blr_dbkey);
	dbKeyNode->dsqlRelation = target;
	missingNode->dsqlArg->nod_arg[0] = reinterpret_cast<dsql_nod*>(dbKeyNode);

	// build a IF (target.RDB$DB_KEY IS NULL)
	IfNode* action = FB_NEW(pool) IfNode(pool);

	action->dsqlCondition = MAKE_node(nod_class_exprnode, 1);
	action->dsqlCondition->nod_arg[0] = reinterpret_cast<dsql_nod*>(missingNode);

	if (insert)
	{
		action->dsqlTrueAction = insert;	// then INSERT
		action->dsqlFalseAction = update;	// else UPDATE/DELETE
	}
	else
	{
		// negate the condition -> IF (target.RDB$DB_KEY IS NOT NULL)

		NotBoolNode* notNode = FB_NEW(pool) NotBoolNode(pool, action->dsqlCondition);

		action->dsqlCondition = MAKE_node(nod_class_exprnode, 1);
		action->dsqlCondition->nod_arg[0] = reinterpret_cast<dsql_nod*>(notNode);

		action->dsqlTrueAction = update;	// then UPDATE/DELETE
	}

	if (!dsqlScratch->isPsql())
	{
		// describe it as EXECUTE_PROCEDURE if RETURNING is present or as INSERT otherwise
		if (input->nod_arg[e_mrg_return])
			dsqlScratch->getStatement()->setType(DsqlCompiledStatement::TYPE_EXEC_PROCEDURE);
		else
			dsqlScratch->getStatement()->setType(DsqlCompiledStatement::TYPE_INSERT);

		dsqlScratch->flags |= DsqlCompilerScratch::FLAG_MERGE;
	}

	// insert the IF inside the FOR SELECT
	forNode->dsqlAction = MAKE_node(nod_class_stmtnode, 1);
	forNode->dsqlAction->nod_arg[0] = (dsql_nod*) action;

	// setup the main node

	if (nullRet)
	{
		dsql_nod* temp = MAKE_node(nod_list, 2);
		temp->nod_arg[0] = nullRet;
		temp->nod_arg[1] = for_select;
		for_select = temp;
	}

	Node* sendNode = (FB_NEW(pool) MergeSendNode(pool, for_select))->dsqlPass(dsqlScratch);

	dsql_nod* sendNod = MAKE_node(nod_class_stmtnode, 1);
	sendNod->nod_arg[0] = (dsql_nod*) sendNode;

	return sendNod;
}


// Changes dsqlScratch->isPsql() value, calls PASS1_node and restore dsqlScratch->isPsql().
dsql_nod* PASS1_node_psql(DsqlCompilerScratch* dsqlScratch, dsql_nod* input, bool psql)
{
	PsqlChanger changer(dsqlScratch, psql);
	return PASS1_node(dsqlScratch, input);
}


// Put recursive non list nodes on the stack.
void PASS1_put_args_on_stack( DsqlCompilerScratch* dsqlScratch, dsql_nod* input, DsqlNodStack& stack)
{
	DEV_BLKCHK(dsqlScratch, dsql_type_req);
	DEV_BLKCHK(input, dsql_type_nod);

	if (input->nod_type != nod_list)
	{
		stack.push(PASS1_node(dsqlScratch, input));
		return;
	}

	dsql_nod** ptr = input->nod_arg;
	for (const dsql_nod* const* const end = ptr + input->nod_count; ptr < end; ptr++)
		PASS1_put_args_on_stack(dsqlScratch, *ptr, stack);
}


/**

 	pass1_relation

    @brief	Prepare a relation name for processing.
 	Allocate a new relation node.


    @param dsqlScratch
    @param input

 **/
static dsql_nod* pass1_relation(DsqlCompilerScratch* dsqlScratch, dsql_nod* input)
{
	thread_db* tdbb = JRD_get_thread_data();

	DEV_BLKCHK(dsqlScratch, dsql_type_req);
	DEV_BLKCHK(input, dsql_type_nod);

	dsql_ctx* context = PASS1_make_context(dsqlScratch, input);
	RecordSourceNode* node = NULL;

	if (context->ctx_relation)
	{
		RelationSourceNode* relNode = FB_NEW(*tdbb->getDefaultPool()) RelationSourceNode(
			*tdbb->getDefaultPool(), context->ctx_relation->rel_name);
		relNode->dsqlContext = context;
		node = relNode;
	}
	else if (context->ctx_procedure)
	{
		ProcedureSourceNode* procNode = FB_NEW(*tdbb->getDefaultPool()) ProcedureSourceNode(
			*tdbb->getDefaultPool(), context->ctx_procedure->prc_name);
		procNode->dsqlContext = context;
		node = procNode;
	}

	fb_assert(node);

	dsql_nod* nod = MAKE_node(nod_class_exprnode, 1);
	nod->nod_arg[0] = reinterpret_cast<dsql_nod*>(node);

	return nod;
}


/**

 	pass1_alias_list

    @brief	The passed alias list fully specifies a relation.
 	The first alias represents a relation specified in
 	the from list at this scope levels.  Subsequent
 	contexts, if there are any, represent base relations
 	in a view stack.  They are used to fully specify a
 	base relation of a view.  The aliases used in the
 	view stack are those used in the view definition.


    @param dsqlScratch
    @param alias_list

 **/
static dsql_ctx* pass1_alias_list(DsqlCompilerScratch* dsqlScratch, dsql_nod* alias_list)
{
	DEV_BLKCHK(dsqlScratch, dsql_type_req);
	DEV_BLKCHK(alias_list, dsql_type_nod);

	dsql_nod** arg = alias_list->nod_arg;
	const dsql_nod* const* const end = arg + alias_list->nod_count;

	// Loop through every alias and find the context for that alias.
	// All aliases should have a corresponding context.
	int aliasCount = alias_list->nod_count;
	USHORT savedScopeLevel = dsqlScratch->scopeLevel;
	dsql_ctx* context = NULL;
	while (aliasCount > 0)
	{
		if (context)
		{
			if (context->ctx_rse && !context->ctx_relation && !context->ctx_procedure)
			{
				// Derived table
				dsqlScratch->scopeLevel++;
				context = pass1_alias(dsqlScratch, context->ctx_childs_derived_table, (dsql_str*) *arg);
			}
			else if (context->ctx_relation)
			{
				// This must be a VIEW
				dsql_nod** startArg = arg;
				dsql_rel* relation = context->ctx_relation;
				// find the base table using the specified alias list, skipping the first one
				// since we already matched it to the context.
				for (; arg < end; arg++, aliasCount--)
				{
					if (!(relation = pass1_base_table(dsqlScratch, relation, (dsql_str*) *arg)))
						break;
				}

				// Found base relation
				if ((aliasCount == 0) && relation)
				{
					// AB: Pretty ugly huh?
					// make up a dummy context to hold the resultant relation.
					thread_db* tdbb = JRD_get_thread_data();
					dsql_ctx* new_context =
						FB_NEW(*tdbb->getDefaultPool()) dsql_ctx(*tdbb->getDefaultPool());
					new_context->ctx_context = context->ctx_context;
					new_context->ctx_relation = relation;

					// concatenate all the contexts to form the alias name;
					// calculate the length leaving room for spaces and a null
					USHORT alias_length = alias_list->nod_count;
					dsql_nod** aliasArg = startArg;
					for (; aliasArg < end; aliasArg++)
					{
						DEV_BLKCHK(*aliasArg, dsql_type_str);
						alias_length += static_cast<USHORT>(((dsql_str*) *aliasArg)->str_length);
					}

					dsql_str* alias = FB_NEW_RPT(*tdbb->getDefaultPool(), alias_length) dsql_str;
					alias->str_length = alias_length;
					new_context->ctx_alias = alias->str_data;

					TEXT* p = alias->str_data;
					for (aliasArg = startArg; aliasArg < end; aliasArg++)
					{
						for (const TEXT* q = ((dsql_str*) *aliasArg)->str_data; *q;)
							*p++ = *q++;
						*p++ = ' ';
					}
					p[-1] = 0;

					context = new_context;
				}
				else
				{
					context = NULL;
				}
			}
			else
			{
				context = NULL;
			}
		}
		else
		{
			context = pass1_alias(dsqlScratch, *dsqlScratch->context, (dsql_str*) *arg);
		}

		if (!context) {
			break;
		}

		arg++;
		aliasCount--;
	}
	dsqlScratch->scopeLevel = savedScopeLevel;

	if (!context)
	{
		// there is no alias or table named %s at this scope level.
		ERRD_post(Arg::Gds(isc_sqlerr) << Arg::Num(-104) <<
				  Arg::Gds(isc_dsql_command_err) <<
				  Arg::Gds(isc_dsql_no_relation_alias) << Arg::Str(((dsql_str*) *arg)->str_data));
	}

	return context;
}


/**

 	pass1_alias

    @brief	The passed relation or alias represents
 	a context which was previously specified
 	in the from list.  Find and return the
 	proper context.


    @param dsqlScratch
    @param alias

 **/
static dsql_ctx* pass1_alias(DsqlCompilerScratch* dsqlScratch, DsqlContextStack& stack, dsql_str* alias)
{
	dsql_ctx* relation_context = NULL;

	DEV_BLKCHK(dsqlScratch, dsql_type_req);
	DEV_BLKCHK(alias, dsql_type_str);

	// CVC: Getting rid of trailing spaces.
	if (alias && alias->str_data) {
		fb_utils::exact_name(alias->str_data);
	}

	// look through all contexts at this scope level
	// to find one that has a relation name or alias
	// name which matches the identifier passed.
	for (DsqlContextStack::iterator itr(stack); itr.hasData(); ++itr)
	{
		dsql_ctx* context = itr.object();
		if (context->ctx_scope_level != dsqlScratch->scopeLevel) {
			continue;
		}

		// check for matching alias.
		if (context->ctx_internal_alias.hasData())
		{
			if (context->ctx_internal_alias == alias->str_data)
				return context;
			continue;
		}

		// If an unnamed derived table and empty alias
		if (context->ctx_rse && !context->ctx_relation && !context->ctx_procedure &&
			alias->str_length == 0)
		{
			relation_context = context;
		}

		// check for matching relation name; aliases take priority so
		// save the context in case there is an alias of the same name;
		// also to check that there is no self-join in the query.
		if (context->ctx_relation && context->ctx_relation->rel_name == alias->str_data)
		{
			if (relation_context)
			{
				// the table %s is referenced twice; use aliases to differentiate
				ERRD_post(Arg::Gds(isc_sqlerr) << Arg::Num(-104) <<
						  Arg::Gds(isc_dsql_command_err) <<
						  Arg::Gds(isc_dsql_self_join) << Arg::Str(alias->str_data));
			}
			relation_context = context;
		}
	}

	return relation_context;
}


/**

 	pass1_alias_concat

    @brief	Concatenate 2 input strings together for
	a new alias string.
	Note: Both input params can be empty.


    @param input1
    @param input2

 **/
static dsql_str* pass1_alias_concat(const dsql_str* input1, const char* input2)
{
	thread_db* tdbb = JRD_get_thread_data();

	DEV_BLKCHK(input1, dsql_type_str);
	DEV_BLKCHK(input2, dsql_type_str);

	int length = (input1 ? input1->str_length : 0);

	if (input1 && input1->str_length && input2)
		++length; // Room for space character.

	if (input2)
		length += strlen(input2);

	dsql_str* output = FB_NEW_RPT(*tdbb->getDefaultPool(), length) dsql_str;
	output->str_length = length;
	TEXT* ptr = output->str_data;

	if (input1)
		strcat(ptr, input1->str_data);

	if (input1 && input1->str_length && input2)
		strcat(ptr, " ");

	if (input2)
		strcat(ptr, input2);

	return output;
}


/**

 	pass1_base_table

    @brief	Check if the relation in the passed context
 	has a base table which matches the passed alias.


    @param dsqlScratch
    @param relation
    @param alias

 **/
static dsql_rel* pass1_base_table( DsqlCompilerScratch* dsqlScratch, const dsql_rel* relation,
	const dsql_str* alias)
{

	DEV_BLKCHK(dsqlScratch, dsql_type_req);
	DEV_BLKCHK(relation, dsql_type_dsql_rel);
	DEV_BLKCHK(alias, dsql_type_str);

	return METD_get_view_relation(dsqlScratch->getTransaction(), dsqlScratch,
		relation->rel_name.c_str(), alias->str_data);
}


/**

 	pass1_returning

    @brief	Compile a RETURNING clause.


    @param dsqlScratch
    @param input

 **/
static dsql_nod* pass1_returning(DsqlCompilerScratch* dsqlScratch, const dsql_nod* input)
{
	thread_db* tdbb = JRD_get_thread_data();

	DEV_BLKCHK(dsqlScratch, dsql_type_req);
	DEV_BLKCHK(input, dsql_type_nod);

	dsql_nod* const source = PASS1_node_psql(dsqlScratch, input->nod_arg[e_ret_source], false);

	dsqlScratch->flags |= DsqlCompilerScratch::FLAG_RETURNING_INTO;
	dsql_nod* const target = PASS1_node(dsqlScratch, input->nod_arg[e_ret_target]);
	dsqlScratch->flags &= ~DsqlCompilerScratch::FLAG_RETURNING_INTO;

	if (!dsqlScratch->isPsql() && target)
	{
		// RETURNING INTO is not allowed syntax for DSQL
		ERRD_post(Arg::Gds(isc_sqlerr) << Arg::Num(-104) <<
				  // Token unknown
				  Arg::Gds(isc_token_err) <<
				  Arg::Gds(isc_random) << Arg::Str("INTO"));
	}
	else if (dsqlScratch->isPsql() && !target)
	{
		// This trick because we don't copy lexer positions when copying lists.
		const dsql_nod* errSrc = input->nod_arg[e_ret_source];
		fb_assert(errSrc->nod_type == nod_list);
		// RETURNING without INTO is not allowed for PSQL
		ERRD_post(Arg::Gds(isc_sqlerr) << Arg::Num(-104) <<
				  // Unexpected end of command
				  Arg::Gds(isc_command_end_err2) << Arg::Num(errSrc->nod_line) <<
													Arg::Num(errSrc->nod_column));
	}

	const int count = source->nod_count;
	fb_assert(count);
	dsql_nod* node = MAKE_node(nod_list, count);

	if (target)
	{
		// PSQL case
		fb_assert(dsqlScratch->isPsql());
		if (count != target->nod_count)
		{
			// count of column list and value list don't match
			ERRD_post(Arg::Gds(isc_sqlerr) << Arg::Num(-804) <<
					  Arg::Gds(isc_dsql_var_count_err));
		}

		dsql_nod** src = source->nod_arg;
		dsql_nod** dst = target->nod_arg;
		dsql_nod** ptr = node->nod_arg;
		for (const dsql_nod* const* const end = ptr + node->nod_count; ptr < end; src++, dst++, ptr++)
		{
			dsql_nod* temp = MAKE_node(nod_assign, e_asgn_count);
			temp->nod_arg[e_asgn_value] = *src;
			temp->nod_arg[e_asgn_field] = *dst;
			*ptr = temp;
		}
	}
	else
	{
		// DSQL case
		fb_assert(!dsqlScratch->isPsql());

		dsql_nod** src = source->nod_arg;
		dsql_nod** ptr = node->nod_arg;
		for (const dsql_nod* const* const end = ptr + node->nod_count; ptr < end; src++, ptr++)
		{
			dsql_par* parameter = MAKE_parameter(dsqlScratch->getStatement()->getReceiveMsg(),
				true, true, 0, *src);
			parameter->par_node = *src;
			MAKE_desc(dsqlScratch, &parameter->par_desc, *src);
			parameter->par_desc.dsc_flags |= DSC_nullable;

			ParameterNode* paramNode = FB_NEW(*tdbb->getDefaultPool()) ParameterNode(
				*tdbb->getDefaultPool());
			paramNode->dsqlParameterIndex = parameter->par_index;
			paramNode->dsqlParameter = parameter;

			dsql_nod* p_node = MAKE_node(nod_class_exprnode, 1);
			p_node->nod_count = 0;
			p_node->nod_arg[0] = reinterpret_cast<dsql_nod*>(paramNode);

			dsql_nod* temp = MAKE_node(nod_assign, e_asgn_count);
			temp->nod_arg[e_asgn_value] = *src;
			temp->nod_arg[e_asgn_field] = p_node;
			*ptr = temp;
		}
	}

	if (!dsqlScratch->isPsql())
		dsqlScratch->getStatement()->setType(DsqlCompiledStatement::TYPE_EXEC_PROCEDURE);

	return node;
}


/**

 	pass1_rse

    @brief	wrapper for pass1_rse_impl
		substitute recursive CTE alias (if needed)
		and call pass1_rse_impl

    @param dsqlScratch
    @param input
    @param order
    @param rows
    @param update_lock
	@param flags

 **/
static dsql_nod* pass1_rse( DsqlCompilerScratch* dsqlScratch, dsql_nod* input, dsql_nod* order,
	dsql_nod* rows, dsql_nod* update_lock, USHORT flags)
{
	string save_alias;
	const bool isRecursive = (input->nod_flags & NOD_SELECT_EXPR_RECURSIVE);

	if (isRecursive)
	{
		fb_assert(dsqlScratch->recursiveCtx);
		save_alias = dsqlScratch->recursiveCtx->ctx_alias;

		dsqlScratch->recursiveCtx->ctx_alias = *dsqlScratch->getNextCTEAlias();
	}

	dsql_nod* ret = pass1_rse_impl(dsqlScratch, input, order, rows, update_lock, flags);

	if (isRecursive)
		dsqlScratch->recursiveCtx->ctx_alias = save_alias;

	return ret;
}


/**

 	pass1_rse_impl

    @brief	Compile a record selection expression.
 	The input node may either be a "select_expression"
 	or a "list" (an implicit union) or a "query specification".


    @param dsqlScratch
    @param input
    @param order
    @param rows
    @param update_lock
	@param flags

 **/
static dsql_nod* pass1_rse_impl( DsqlCompilerScratch* dsqlScratch, dsql_nod* input, dsql_nod* order,
	dsql_nod* rows, dsql_nod* update_lock, USHORT flags)
{
	DEV_BLKCHK(dsqlScratch, dsql_type_req);
	DEV_BLKCHK(input, dsql_type_nod);
	DEV_BLKCHK(order, dsql_type_nod);

	thread_db* tdbb = JRD_get_thread_data();
	MemoryPool& pool = *tdbb->getDefaultPool();

	// Verify if we're processing view fields and reset flag to not pass to
	// more than required inner nodes.
	const USHORT viewFlags = input->nod_flags | (flags & NOD_SELECT_EXPR_VIEW_FIELDS);
	flags &= ~NOD_SELECT_EXPR_VIEW_FIELDS;

	if (input->nod_type == nod_select_expr)
	{
		dsql_nod* node_with = input->nod_arg[e_sel_with_list];
		try
		{
			if (node_with)
				dsqlScratch->addCTEs(node_with);

			dsql_nod* ret =
				pass1_rse(dsqlScratch, input->nod_arg[e_sel_query_spec],
						input->nod_arg[e_sel_order], input->nod_arg[e_sel_rows],
						update_lock, viewFlags);

			if (node_with)
			{
				dsqlScratch->checkUnusedCTEs();
				dsqlScratch->clearCTEs();
			}

			return ret;
		}
		catch (const Firebird::Exception&)
		{
			if (node_with)
				dsqlScratch->clearCTEs();
			throw;
		}
	}
	else if (input->nod_type == nod_list)
	{
		fb_assert(input->nod_count > 1);
		return pass1_union(dsqlScratch, input, order, rows, update_lock, flags);
	}

	RseNode* inputRse = ExprNode::as<RseNode>(input);
	fb_assert(inputRse);

	// Save the original base of the context stack and process relations

	RseNode* targetRse = FB_NEW(pool) RseNode(pool);
	RseNode* rse = targetRse;

	dsql_nod* rseNod = MAKE_node(nod_class_exprnode, 1);
	rseNod->nod_arg[0] = reinterpret_cast<dsql_nod*>(rse);

	if (update_lock)
		rse->flags |= RseNode::FLAG_WRITELOCK;

	dsql_nod* list = rse->dsqlStreams = PASS1_node_psql(dsqlScratch, inputRse->dsqlFrom, false);

	{ // scope block
		RelationSourceNode* relNode;
		const dsql_rel* relation;

		if (update_lock &&
			(list->nod_count != 1 || !(relNode = ExprNode::as<RelationSourceNode>(list->nod_arg[0])) ||
				!(relation = relNode->dsqlContext->ctx_relation) ||
				(relation->rel_flags & REL_view) || (relation->rel_flags & REL_external)))
		{
			ERRD_post(Arg::Gds(isc_sqlerr) << Arg::Num(-104) <<
					  // Token unknown
					  Arg::Gds(isc_token_err) <<
					  Arg::Gds(isc_random) << Arg::Str("WITH LOCK"));
		}
	} // end scope block

	// Process LIMIT and/or ROWS, if any

	if ((inputRse->dsqlFirst || inputRse->dsqlSkip) && rows)
	{
		ERRD_post(Arg::Gds(isc_sqlerr) << Arg::Num(-104) <<
				  // Token unknown
				  Arg::Gds(isc_token_err) <<
				  Arg::Gds(isc_random) << Arg::Str("ROWS"));
	}
	else if (rows)
	{
		pass1_limit(dsqlScratch, rows->nod_arg[e_rows_length], rows->nod_arg[e_rows_skip], rse);
	}
	else if (inputRse->dsqlFirst || inputRse->dsqlSkip)
	{
		pass1_limit(dsqlScratch, inputRse->dsqlFirst, inputRse->dsqlSkip, rse);
	}

	// Process boolean, if any

	if (inputRse->dsqlWhere)
	{
		++dsqlScratch->inWhereClause;
		rse->dsqlWhere = PASS1_node_psql(dsqlScratch, inputRse->dsqlWhere, false);
		--dsqlScratch->inWhereClause;

		// AB: An aggregate pointing to it's own parent_context isn't
		// allowed, HAVING should be used instead
		if (Aggregate2Finder::find(dsqlScratch->scopeLevel, FIELD_MATCH_TYPE_EQUAL, false,
				rse->dsqlWhere))
		{
			// Cannot use an aggregate in a WHERE clause, use HAVING instead
			ERRD_post(Arg::Gds(isc_sqlerr) << Arg::Num(-104) <<
					  Arg::Gds(isc_dsql_agg_where_err));
		}
	}

#ifdef DSQL_DEBUG
	if (DSQL_debug & 16)
	{
		dsql_trace("PASS1_rse input tree:");
		DSQL_pretty(input, 0);
	}
#endif

	// Process select list, if any. If not, generate one
	dsql_nod* selectList = inputRse->dsqlSelectList;
	// First expand select list, this will expand nodes with asterisk.
	++dsqlScratch->inSelectList;
	selectList = pass1_expand_select_list(dsqlScratch, selectList, rse->dsqlStreams);

	if ((flags & NOD_SELECT_EXPR_VALUE) && (!selectList || selectList->nod_count > 1))
	{
		// More than one column (or asterisk) is specified in column_singleton
		ERRD_post(Arg::Gds(isc_sqlerr) << Arg::Num(-104) <<
				  Arg::Gds(isc_dsql_command_err) <<
				  Arg::Gds(isc_dsql_count_mismatch));
	}

	// Pass select list
	rse->dsqlSelectList = pass1_sel_list(dsqlScratch, selectList,
		(viewFlags & NOD_SELECT_EXPR_VIEW_FIELDS));
	--dsqlScratch->inSelectList;

	// Process ORDER clause, if any
	if (order)
	{
		++dsqlScratch->inOrderByClause;
		rse->dsqlOrder = pass1_sort(dsqlScratch, order, selectList);
		--dsqlScratch->inOrderByClause;
	}

	// A GROUP BY, HAVING, or any aggregate function in the select list
	// will force an aggregate
	dsql_ctx* parent_context = NULL;
	RseNode* parentRse = NULL;
	AggregateSourceNode* aggregate = NULL;

	if (inputRse->dsqlGroup ||
		inputRse->dsqlHaving ||
		(rse->dsqlSelectList && AggregateFinder::find(dsqlScratch, false, rse->dsqlSelectList)) ||
		(rse->dsqlOrder && AggregateFinder::find(dsqlScratch, false, rse->dsqlOrder)))
	{
		// dimitr: don't allow WITH LOCK for aggregates
		if (update_lock)
		{
			ERRD_post(Arg::Gds(isc_sqlerr) << Arg::Num(-104) <<
					  // Token unknown
					  Arg::Gds(isc_token_err) <<
					  Arg::Gds(isc_random) << Arg::Str("WITH LOCK"));
		}

		parent_context = FB_NEW(*tdbb->getDefaultPool()) dsql_ctx(*tdbb->getDefaultPool());
		parent_context->ctx_scope_level = dsqlScratch->scopeLevel;

		// When we're in a outer-join part mark context for it.
		if (dsqlScratch->inOuterJoin)
			parent_context->ctx_flags |= CTX_outer_join;
		parent_context->ctx_in_outer_join = dsqlScratch->inOuterJoin;

		aggregate = FB_NEW(pool) AggregateSourceNode(pool);
		aggregate->dsqlContext = parent_context;
		aggregate->dsqlRse = rseNod;
		parentRse = targetRse = FB_NEW(pool) RseNode(pool);
		parentRse->dsqlStreams = list = MAKE_node(nod_list, 1);

		dsql_nod* aggregateNod = MAKE_node(nod_class_exprnode, 1);
		aggregateNod->nod_arg[0] = reinterpret_cast<dsql_nod*>(aggregate);
		list->nod_arg[0] = aggregateNod;

		if (rse->dsqlFirst)
		{
			parentRse->dsqlFirst = rse->dsqlFirst;
			rse->dsqlFirst = NULL;
		}

		if (rse->dsqlSkip)
		{
			parentRse->dsqlSkip = rse->dsqlSkip;
			rse->dsqlSkip = NULL;
		}

		dsqlScratch->context->push(parent_context);
		// replace original contexts with parent context
		remap_streams_to_parent_context(rse->dsqlStreams, parent_context);
	}

	// Process GROUP BY clause, if any
	if (inputRse->dsqlGroup)
	{
		// if there are positions in the group by clause then replace them
		// by the (newly pass) items from the select_list
		++dsqlScratch->inGroupByClause;
		aggregate->dsqlGroup = pass1_group_by_list(dsqlScratch, inputRse->dsqlGroup, selectList);
		--dsqlScratch->inGroupByClause;

		// AB: An field pointing to another parent_context isn't
		// allowed and GROUP BY items can't contain aggregates
		if (FieldFinder::find(dsqlScratch->scopeLevel, FIELD_MATCH_TYPE_LOWER, aggregate->dsqlGroup) ||
			Aggregate2Finder::find(dsqlScratch->scopeLevel, FIELD_MATCH_TYPE_LOWER_EQUAL,
				false, aggregate->dsqlGroup))
		{
			// Cannot use an aggregate in a GROUP BY clause
			ERRD_post(Arg::Gds(isc_sqlerr) << Arg::Num(-104) <<
					  Arg::Gds(isc_dsql_agg_group_err));
		}
	}

	// Parse a user-specified access PLAN
	rse->dsqlPlan = PASS1_node_psql(dsqlScratch, inputRse->dsqlPlan, false);

	// AB: Pass select-items for distinct operation again, because for
	// sub-selects a new context number should be generated
	if (inputRse->dsqlDistinct)
	{
		if (update_lock)
		{
			ERRD_post(Arg::Gds(isc_sqlerr) << Arg::Num(-104) <<
					  // Token unknown
					  Arg::Gds(isc_token_err) <<
					  Arg::Gds(isc_random) << Arg::Str("WITH LOCK"));
		}

		++dsqlScratch->inSelectList;
		// ASF: We pass false to viewFields parameter here because these expressions are
		// generated inside the view body, and not in view fields.
		targetRse->dsqlDistinct = pass1_sel_list(dsqlScratch, selectList, false);
		--dsqlScratch->inSelectList;

		// sort, group and distinct have the same limit for now
		if (selectList->nod_count > MAX_SORT_ITEMS)
		{
			// Cannot have more than 255 items in DISTINCT list.
			ERRD_post(Arg::Gds(isc_sqlerr) << Arg::Num(-104) <<
					  Arg::Gds(isc_dsql_command_err) <<
					  Arg::Gds(isc_dsql_max_distinct_items));
		}
	}

	if (parent_context)
	{
		// Reset context of select items to point to the parent stream

		parentRse->dsqlSelectList = FieldRemapper::remap(dsqlScratch, parent_context, false,
			rse->dsqlSelectList);
		rse->dsqlSelectList = NULL;

		// AB: Check for invalid constructions inside selected-items list
		list = parentRse->dsqlSelectList;

		{ // scope block
			const dsql_nod* const* ptr = list->nod_arg;
			for (const dsql_nod* const* const end = ptr + list->nod_count; ptr < end; ptr++)
			{
				if (InvalidReferenceFinder::find(parent_context, aggregate->dsqlGroup, *ptr))
				{
					// Invalid expression in the select list
					// (not contained in either an aggregate or the GROUP BY clause)
					ERRD_post(Arg::Gds(isc_sqlerr) << Arg::Num(-104) <<
							  Arg::Gds(isc_dsql_agg_column_err) << Arg::Str("select list"));
				}
			}
		} // end scope block

		// Reset context of order items to point to the parent stream

		if (order)
		{
			parentRse->dsqlOrder = FieldRemapper::remap(dsqlScratch, parent_context,
				false, rse->dsqlOrder);
			rse->dsqlOrder = NULL;

			// AB: Check for invalid contructions inside the ORDER BY clause
			list = targetRse->dsqlOrder;
			const dsql_nod* const* ptr = list->nod_arg;
			for (const dsql_nod* const* const end = ptr + list->nod_count; ptr < end; ptr++)
			{
				if (InvalidReferenceFinder::find(parent_context, aggregate->dsqlGroup, *ptr))
				{
					// Invalid expression in the ORDER BY clause
					// (not contained in either an aggregate or the GROUP BY clause)
					ERRD_post(Arg::Gds(isc_sqlerr) << Arg::Num(-104) <<
							  Arg::Gds(isc_dsql_agg_column_err) << Arg::Str("ORDER BY clause"));
				}
			}
		}

		// And, of course, reduction clauses must also apply to the parent
		if (inputRse->dsqlDistinct)
		{
			parentRse->dsqlDistinct = FieldRemapper::remap(dsqlScratch, parent_context,
				false, parentRse->dsqlDistinct);
		}

		// Process HAVING clause, if any

		if (inputRse->dsqlHaving)
		{
			++dsqlScratch->inHavingClause;
			parentRse->dsqlWhere = PASS1_node_psql(dsqlScratch, inputRse->dsqlHaving, false);
			--dsqlScratch->inHavingClause;

			parentRse->dsqlWhere = FieldRemapper::remap(dsqlScratch, parent_context,
				false, parentRse->dsqlWhere);

			// AB: Check for invalid contructions inside the HAVING clause

			if (InvalidReferenceFinder::find(parent_context, aggregate->dsqlGroup,
					parentRse->dsqlWhere))
			{
				// Invalid expression in the HAVING clause
				// (neither an aggregate nor contained in the GROUP BY clause)
				ERRD_post(Arg::Gds(isc_sqlerr) << Arg::Num(-104) <<
						  Arg::Gds(isc_dsql_agg_having_err) << Arg::Str("HAVING clause"));
			}

			if (AggregateFinder::find(dsqlScratch, true, parentRse->dsqlWhere))
			{
				// Cannot use an aggregate in a WHERE clause, use HAVING instead
				ERRD_post(Arg::Gds(isc_sqlerr) << Arg::Num(-104) <<
						  Arg::Gds(isc_dsql_agg_where_err));
			}
		}

		rse = parentRse;
		rseNod = MAKE_node(nod_class_exprnode, 1);
		rseNod->nod_arg[0] = reinterpret_cast<dsql_nod*>(rse);

		parent_context->ctx_context = dsqlScratch->contextNumber++;
	}

	const bool sortWindow = rse->dsqlOrder && AggregateFinder::find(dsqlScratch, true, rse->dsqlOrder);

	// WINDOW functions
	if ((rse->dsqlSelectList && AggregateFinder::find(dsqlScratch, true, rse->dsqlSelectList)) ||
		sortWindow)
	{
		AutoSetRestore<bool> autoProcessingWindow(&dsqlScratch->processingWindow, true);

		parent_context = FB_NEW(*tdbb->getDefaultPool()) dsql_ctx(*tdbb->getDefaultPool());
		parent_context->ctx_scope_level = dsqlScratch->scopeLevel;

		AggregateSourceNode* window = FB_NEW(pool) AggregateSourceNode(pool);
		window->dsqlContext = parent_context;
		window->dsqlRse = rseNod;
		window->dsqlWindow = true;

		dsql_nod* windowNod = MAKE_node(nod_class_exprnode, 1);
		windowNod->nod_arg[0] = reinterpret_cast<dsql_nod*>(window);

		parentRse = targetRse = FB_NEW(pool) RseNode(pool);
		parentRse->dsqlStreams = list = MAKE_node(nod_list, 1);
		list->nod_arg[0] = windowNod;

		if (rse->flags & RseNode::FLAG_WRITELOCK)
		{
			parentRse->flags |= RseNode::FLAG_WRITELOCK;
			rse->flags &= ~RseNode::FLAG_WRITELOCK;
		}

		if (rse->dsqlFirst)
		{
			parentRse->dsqlFirst = rse->dsqlFirst;
			rse->dsqlFirst = NULL;
		}

		if (rse->dsqlSkip)
		{
			parentRse->dsqlSkip = rse->dsqlSkip;
			rse->dsqlSkip = NULL;
		}

		dsqlScratch->context->push(parent_context);
		// replace original contexts with parent context
		remap_streams_to_parent_context(rse->dsqlStreams, parent_context);

		if (aggregate)
		{
			// Check for invalid contructions inside selected-items list
			list = rse->dsqlSelectList;
			const dsql_nod* const* ptr = list->nod_arg;
			for (const dsql_nod* const* const end = ptr + list->nod_count; ptr < end; ptr++)
			{
				if (InvalidReferenceFinder::find(parent_context, aggregate->dsqlGroup, *ptr))
				{
					// Invalid expression in the select list
					// (not contained in either an aggregate or the GROUP BY clause)
					ERRD_post(Arg::Gds(isc_sqlerr) << Arg::Num(-104) <<
							  Arg::Gds(isc_dsql_agg_column_err) << Arg::Str("select list"));
				}
			}
		}

		parentRse->dsqlSelectList = FieldRemapper::remap(dsqlScratch, parent_context, true,
			rse->dsqlSelectList);

		// Remap the nodes to the partition context.
		for (size_t i = 0, mapCount = parent_context->ctx_win_maps.getCount(); i < mapCount; ++i)
		{
			PartitionMap* partitionMap = parent_context->ctx_win_maps[i];
			if (partitionMap->partition)
			{
				partitionMap->partitionRemapped = PASS1_node(dsqlScratch, partitionMap->partition);
				partitionMap->partitionRemapped = FieldRemapper::remap(dsqlScratch, parent_context,
					true, partitionMap->partitionRemapped, partitionMap->partition,
					partitionMap->order);
			}
		}

		rse->dsqlSelectList = NULL;

		if (order)
		{
			if (aggregate)
			{
				// Check for invalid contructions inside the order-by list
				list = rse->dsqlOrder;
				const dsql_nod* const* ptr = list->nod_arg;
				for (const dsql_nod* const* const end = ptr + list->nod_count; ptr < end; ptr++)
				{
					if (InvalidReferenceFinder::find(parent_context, aggregate->dsqlGroup, *ptr))
					{
						// Invalid expression in the ORDER BY list
						// (not contained in either an aggregate or the GROUP BY clause)
						ERRD_post(Arg::Gds(isc_sqlerr) << Arg::Num(-104) <<
								  Arg::Gds(isc_dsql_agg_column_err) << Arg::Str("ORDER BY list"));
					}
				}
			}

			parentRse->dsqlOrder = FieldRemapper::remap(dsqlScratch, parent_context,
				true, rse->dsqlOrder);

			rse->dsqlOrder = NULL;
		}

		// And, of course, reduction clauses must also apply to the parent
		if (rse->dsqlDistinct)
		{
			parentRse->dsqlDistinct = FieldRemapper::remap(dsqlScratch, parent_context,
				true, rse->dsqlDistinct);
			rse->dsqlDistinct = NULL;
		}

		rse = parentRse;
		rseNod = MAKE_node(nod_class_exprnode, 1);
		rseNod->nod_arg[0] = reinterpret_cast<dsql_nod*>(rse);
	}

	rseNod->nod_flags = flags;

	return rseNod;
}


/**

 	pass1_sel_list

    @brief	Compile a select list.

    @param dsqlScratch
    @param input

 **/
static dsql_nod* pass1_sel_list(DsqlCompilerScratch* dsqlScratch, dsql_nod* input, bool viewFields)
{
	DEV_BLKCHK(dsqlScratch, dsql_type_req);
	DEV_BLKCHK(input, dsql_type_nod);

	DsqlNodStack stack;
	dsql_nod** ptr = input->nod_arg;
	for (const dsql_nod* const* const end = ptr + input->nod_count; ptr < end; ptr++)
	{
		if (viewFields)
			dsqlScratch->hiddenVarsNumber = 0;

		DEV_BLKCHK(*ptr, dsql_type_nod);
		stack.push(PASS1_node_psql(dsqlScratch, *ptr, false));

		if (viewFields)
			dsqlScratch->hiddenVarsNumber = 0;
	}
	dsql_nod* node = MAKE_list(stack);

	return node;
}


/**

 	pass1_sort

    @brief	Process ORDER BY list, which may contain
			an ordinal or alias which references the
			select list.

    @param dsqlScratch
    @param input
    @param selectList

 **/
static dsql_nod* pass1_sort( DsqlCompilerScratch* dsqlScratch, dsql_nod* input, dsql_nod* selectList)
{
	DEV_BLKCHK(dsqlScratch, dsql_type_req);
	DEV_BLKCHK(input, dsql_type_nod);
	DEV_BLKCHK(selectList, dsql_type_nod);

	if (input->nod_type != nod_list)
	{
		ERRD_post(Arg::Gds(isc_sqlerr) << Arg::Num(-104) <<
				  Arg::Gds(isc_dsql_command_err) <<
				  // invalid ORDER BY clause
				  Arg::Gds(isc_order_by_err));
	}

	if (input->nod_count > MAX_SORT_ITEMS)
	{
		ERRD_post(Arg::Gds(isc_sqlerr) << Arg::Num(-104) <<
				  Arg::Gds(isc_dsql_command_err) <<
				  Arg::Gds(isc_order_by_err) <<
				  // invalid ORDER BY clause, cannot sort on more than 255 items
				  Arg::Gds(isc_dsql_max_sort_items));
	}

	// Node is simply to be rebuilt -- just recurse merrily

	dsql_nod* node = MAKE_node(input->nod_type, input->nod_count);
	dsql_nod** ptr2 = node->nod_arg;

	for (int sortloop = 0; sortloop < input->nod_count; sortloop++)
	{
		DEV_BLKCHK(input->nod_arg[sortloop], dsql_type_nod);
		dsql_nod* node1 = input->nod_arg[sortloop];
		if (node1->nod_type != nod_order)
		{
			ERRD_post(Arg::Gds(isc_sqlerr) << Arg::Num(-104) <<
					  Arg::Gds(isc_dsql_command_err) <<
					  // invalid ORDER BY clause
					  Arg::Gds(isc_order_by_err));
		}
		dsql_nod* node2 = MAKE_node(nod_order, e_order_count);
		node2->nod_arg[e_order_flag] = node1->nod_arg[e_order_flag]; // asc/desc flag
		node2->nod_arg[e_order_nulls] = node1->nod_arg[e_order_nulls]; // nulls first/last flag

		const dsql_str* collate = NULL;

		// get node of value to be ordered by
		node1 = node1->nod_arg[e_order_field];

		if (node1->nod_type == nod_collate)
		{
			collate = (dsql_str*) node1->nod_arg[e_coll_target];
			// substitute nod_collate with its argument (real value)
			node1 = node1->nod_arg[e_coll_source];
		}

		LiteralNode* literal;

		if (node1->nod_type == nod_field_name)
		{
			// check for alias or field node
			node1 = pass1_field(dsqlScratch, node1, false, selectList);
		}
		else if ((literal = ExprNode::as<LiteralNode>(node1)) && literal->litDesc.dsc_dtype == dtype_long)
		{
			const ULONG position = literal->getSlong();

			if (position < 1 || !selectList || position > (ULONG) selectList->nod_count)
			{
				ERRD_post(Arg::Gds(isc_sqlerr) << Arg::Num(-104) <<
						  // Invalid column position used in the ORDER BY clause
						  Arg::Gds(isc_dsql_column_pos_err) << Arg::Str("ORDER BY"));
			}

			// substitute ordinal with appropriate field
			node1 = PASS1_node_psql(dsqlScratch, selectList->nod_arg[position - 1], false);
		}
		else
			node1 = PASS1_node_psql(dsqlScratch, node1, false);

		if (collate)
		{
			// finally apply collation order, if necessary
			node1 = pass1_collate(dsqlScratch, node1, collate);
		}

		// store actual value to be ordered by
		node2->nod_arg[e_order_field] = node1;
		*ptr2++ = node2;
	}

	return node;
}


/**

 	pass1_union

    @brief	Handle a UNION of substreams, generating
 	a mapping of all the fields and adding an
 	implicit PROJECT clause to ensure that all
 	the records returned are unique.


    @param dsqlScratch
    @param input
    @param order_list
	@param rows
	@param update_lock
	@param flags

 **/
static dsql_nod* pass1_union( DsqlCompilerScratch* dsqlScratch, dsql_nod* input, dsql_nod* order_list,
	dsql_nod* rows, dsql_nod* update_lock, USHORT flags)
{
	DEV_BLKCHK(dsqlScratch, dsql_type_req);
	DEV_BLKCHK(input, dsql_type_nod);
	DEV_BLKCHK(order_list, dsql_type_nod);

	thread_db* tdbb = JRD_get_thread_data();
	MemoryPool& pool = *tdbb->getDefaultPool();

	// set up the rse node for the union.
	RseNode* unionRse = FB_NEW(pool) RseNode(pool);
	UnionSourceNode* unionSource = FB_NEW(pool) UnionSourceNode(pool);

	dsql_nod* unionNod = unionRse->dsqlStreams = MAKE_node(nod_class_exprnode, 1);
	unionNod->nod_arg[0] = reinterpret_cast<dsql_nod*>(unionSource);
	unionNod->nod_flags = input->nod_flags;

	// generate a context for the union itself.
	dsql_ctx* union_context = FB_NEW(*tdbb->getDefaultPool()) dsql_ctx(*tdbb->getDefaultPool());

	if (input->nod_flags & NOD_UNION_RECURSIVE)
		union_context->ctx_context = dsqlScratch->recursiveCtxId;
	else
		union_context->ctx_context = dsqlScratch->contextNumber++;

	unionSource->dsqlClauses = MAKE_node(nod_list, input->nod_count);

	// process all the sub-rse's.
	{ // scope block
		dsql_nod** uptr = unionSource->dsqlClauses->nod_arg;
		const DsqlContextStack::const_iterator base(*dsqlScratch->context);
		dsql_nod** ptr = input->nod_arg;

		for (const dsql_nod* const* const end = ptr + input->nod_count; ptr < end; ++ptr, ++uptr)
		{
			dsqlScratch->scopeLevel++;
			*uptr = pass1_rse(dsqlScratch, *ptr, NULL, NULL, NULL, 0);
			dsqlScratch->scopeLevel--;

			while (*(dsqlScratch->context) != base)
				dsqlScratch->unionContext.push(dsqlScratch->context->pop());

			// Push recursive context after initial select has been processed.
			// Corresponding pop occurs in pass1_derived_table
			if ((input->nod_flags & NOD_UNION_RECURSIVE) && (ptr == input->nod_arg))
				dsqlScratch->context->push(dsqlScratch->recursiveCtx);
		}
	} // end scope block

	// generate the list of fields to select.
	dsql_nod* items = ExprNode::as<RseNode>(unionSource->dsqlClauses->nod_arg[0])->dsqlSelectList;

	// loop through the list nodes, checking to be sure that they have the
	// same number of items

	for (int i = 1; i < unionSource->dsqlClauses->nod_count; ++i)
	{
		const dsql_nod* nod1 = ExprNode::as<RseNode>(unionSource->dsqlClauses->nod_arg[i])->dsqlSelectList;

		if (items->nod_count != nod1->nod_count)
		{
			ERRD_post(Arg::Gds(isc_sqlerr) << Arg::Num(-104) <<
					  Arg::Gds(isc_dsql_command_err) <<
					  // overload of msg
					  Arg::Gds(isc_dsql_count_mismatch));
		}
	}

	// Comment below belongs to the old code (way a union was handled).

	// SQL II, section 9.3, pg 195 governs which data types
	// are considered equivalent for a UNION
	// The following restriction is in some ways more restrictive
	// (cannot UNION CHAR with VARCHAR for instance)
	// (or cannot union CHAR of different lengths)
	// and in someways less restrictive
	// (SCALE is not looked at)
	// Workaround: use a direct CAST() dsqlScratch in the SQL
	// dsqlScratch to force desired datatype.

	// loop through the list nodes and cast whenever possible.
	dsql_nod* tmp_list = MAKE_node(nod_list, unionSource->dsqlClauses->nod_count);

	for (int j = 0; j < items->nod_count; ++j)
	{
		for (int i = 0; i < unionSource->dsqlClauses->nod_count; ++i)
		{
			dsql_nod* nod1 = ExprNode::as<RseNode>(unionSource->dsqlClauses->nod_arg[i])->dsqlSelectList;
			MAKE_desc(dsqlScratch, &nod1->nod_arg[j]->nod_desc, nod1->nod_arg[j]);
			tmp_list->nod_arg[i] = nod1->nod_arg[j];

			// We look only at the items->nod_arg[] when creating the
			// output descriptors. Make sure that the sub-rses
			// descriptor flags are copied onto items->nod_arg[]->nod_desc.
			// Bug 65584.
			// -Sudesh 07/28/1999.
			if (i > 0)
			{
				if (nod1->nod_arg[j]->nod_desc.dsc_flags & DSC_nullable)
					items->nod_arg[j]->nod_desc.dsc_flags |= DSC_nullable;
			}
		}

		dsc desc;
		MAKE_desc_from_list(dsqlScratch, &desc, tmp_list, "UNION");
		// Only mark upper node as a NULL node when all sub-nodes are NULL
		items->nod_arg[j]->nod_desc.dsc_flags &= ~DSC_null;
		items->nod_arg[j]->nod_desc.dsc_flags |= (desc.dsc_flags & DSC_null);

		for (int i = 0; i < unionSource->dsqlClauses->nod_count; ++i)
			pass1_union_auto_cast(dsqlScratch, unionSource->dsqlClauses->nod_arg[i], desc, j);
	}

	items = ExprNode::as<RseNode>(unionSource->dsqlClauses->nod_arg[0])->dsqlSelectList;

	// Create mappings for union.

	dsql_nod* union_items = MAKE_node(nod_list, items->nod_count);

	{ // scope block
		USHORT count = 0;
		dsql_nod** uptr = items->nod_arg;
		dsql_nod** ptr = union_items->nod_arg;

		for (const dsql_nod* const* const end = ptr + union_items->nod_count; ptr < end; ptr++)
		{
			// Set up the dsql_map* between the sub-rses and the union context.
			dsql_map* map = union_context->ctx_map = FB_NEW(*tdbb->getDefaultPool()) dsql_map;
			map->map_position = count++;
			map->map_node = *uptr++;
			map->map_next = union_context->ctx_map;
			map->map_partition = NULL;

			DsqlMapNode* mapNode = FB_NEW(*tdbb->getDefaultPool()) DsqlMapNode(*tdbb->getDefaultPool(),
				union_context, map);

		    *ptr = MAKE_node(nod_class_exprnode, 1);
		    (*ptr)->nod_arg[0] = reinterpret_cast<dsql_nod*>(mapNode);
		}

		unionRse->dsqlSelectList = union_items;
	} // end scope block

	// Process ORDER clause, if any.
	if (order_list)
	{
		dsql_nod* sort = MAKE_node(nod_list, order_list->nod_count);
		dsql_nod** uptr = sort->nod_arg;
		dsql_nod** ptr = order_list->nod_arg;

		for (const dsql_nod* const* const end = ptr + order_list->nod_count; ptr < end; ptr++, uptr++)
		{
			dsql_nod* order1 = *ptr;
			const dsql_str* collate = 0;
			const dsql_nod* position = order1->nod_arg[e_order_field];

			if (position->nod_type == nod_collate)
			{
				collate = (dsql_str*) position->nod_arg[e_coll_target];
				position = position->nod_arg[e_coll_source];
			}

			const LiteralNode* literal = ExprNode::as<LiteralNode>(position);

			if (!literal || literal->litDesc.dsc_dtype != dtype_long)
			{
				ERRD_post(Arg::Gds(isc_sqlerr) << Arg::Num(-104) <<
						  Arg::Gds(isc_dsql_command_err) <<
						  // invalid ORDER BY clause.
						  Arg::Gds(isc_order_by_err));
			}

			const SLONG number = literal->getSlong();

			if (number < 1 || number > union_items->nod_count)
			{
				ERRD_post(Arg::Gds(isc_sqlerr) << Arg::Num(-104) <<
						  Arg::Gds(isc_dsql_command_err) <<
						  // invalid ORDER BY clause.
						  Arg::Gds(isc_order_by_err));
			}

			// make a new order node pointing at the Nth item in the select list.
			dsql_nod* order2 = MAKE_node(nod_order, e_order_count);
			*uptr = order2;
			order2->nod_arg[e_order_field] = union_items->nod_arg[number - 1];
			order2->nod_arg[e_order_flag] = order1->nod_arg[e_order_flag];

			if (collate)
			{
				order2->nod_arg[e_order_field] =
					pass1_collate(dsqlScratch, order2->nod_arg[e_order_field], collate);
			}

			order2->nod_arg[e_order_nulls] = order1->nod_arg[e_order_nulls];
		}

		unionRse->dsqlOrder = sort;
	}

	if (rows)
	{
		pass1_limit(dsqlScratch, rows->nod_arg[e_rows_length], rows->nod_arg[e_rows_skip], unionRse);
	}

	// PROJECT on all the select items unless UNION ALL was specified.
	if (!(input->nod_flags & NOD_UNION_ALL))
	{
		if (update_lock)
		{
			ERRD_post(Arg::Gds(isc_sqlerr) << Arg::Num(-104) <<
					  // Token unknown
					  Arg::Gds(isc_token_err) <<
					  Arg::Gds(isc_random) << Arg::Str("WITH LOCK"));
		}

		unionRse->dsqlDistinct = union_items;
	}

	if (update_lock)
		unionRse->flags |= RseNode::FLAG_WRITELOCK;

	dsql_nod* unionRseNod = MAKE_node(nod_class_exprnode, 1);
	unionRseNod->nod_arg[0] = reinterpret_cast<dsql_nod*>(unionRse);
	unionRseNod->nod_flags = flags;

	return unionRseNod;
}


/**

 	pass1_union_auto_cast

    @brief	Auto cast types to the same type by the rules from
	MAKE_desc_from_list. SELECT X1 FROM .. UNION SELECT X2 FROM ..
	Items X1..Xn are collected together to make the cast-descriptor, this
	was done by the caller (param desc and input is the collection).
	Then is a cast generated (or reused) for every X item if it has
	another descriptor than the param desc.
	Position tells us which column-nr we are processing.

    @param input
    @param desc
    @param position
    @param in_select_list

 **/
static void pass1_union_auto_cast(DsqlCompilerScratch* dsqlScratch, dsql_nod* input,
	const dsc& desc, SSHORT position, bool in_select_list)
{
	thread_db* tdbb = JRD_get_thread_data();

	DEV_BLKCHK(input, dsql_type_nod);

	switch (input->nod_type)
	{
		case nod_list:
			if (in_select_list)
			{
				if (position < 0 || position >= input->nod_count)
				{
					// Internal dsql error: column position out of range in pass1_union_auto_cast
					ERRD_post(Arg::Gds(isc_sqlerr) << Arg::Num(-104) <<
							  Arg::Gds(isc_dsql_command_err) <<
							  Arg::Gds(isc_dsql_auto_field_bad_pos));
				}
				else
				{
					dsql_nod* select_item = input->nod_arg[position];
					MAKE_desc(dsqlScratch, &select_item->nod_desc, select_item);

					if (select_item->nod_desc.dsc_dtype != desc.dsc_dtype ||
						select_item->nod_desc.dsc_length != desc.dsc_length ||
						select_item->nod_desc.dsc_scale != desc.dsc_scale ||
						select_item->nod_desc.dsc_sub_type != desc.dsc_sub_type)
					{
						// Because this select item has a different descriptor then
						// our finally descriptor CAST it.
						dsql_nod* cast_node = NULL;
						dsql_nod* alias_node = NULL;
						DerivedFieldNode* derivedField;

						// Pick a existing cast if available else make a new one.
						if (select_item->nod_type == nod_alias &&
							select_item->nod_arg[e_alias_value] &&
							ExprNode::is<CastNode>(select_item->nod_arg[e_alias_value]))
						{
							cast_node = select_item->nod_arg[e_alias_value];
						}
						else if ((derivedField = ExprNode::as<DerivedFieldNode>(select_item)) &&
							ExprNode::is<CastNode>(derivedField->dsqlValue))
						{
							cast_node = derivedField->dsqlValue;
						}
						else if (ExprNode::is<CastNode>(select_item))
							cast_node = select_item;
						else
						{
							CastNode* castNode = FB_NEW(*tdbb->getDefaultPool()) CastNode(
								*tdbb->getDefaultPool());

							castNode->dsqlField = FB_NEW(*tdbb->getDefaultPool()) dsql_fld(
								*tdbb->getDefaultPool());

							cast_node = MAKE_node(nod_class_exprnode, 1);
							cast_node->nod_arg[0] = reinterpret_cast<dsql_nod*>(castNode);

							// We want to leave the ALIAS node on his place, because a UNION
							// uses the select_items from the first sub-rse to determine the
							// columnname.
							if (select_item->nod_type == nod_alias)
								castNode->dsqlSource = select_item->nod_arg[e_alias_value];
							else if ((derivedField = ExprNode::as<DerivedFieldNode>(select_item)))
								castNode->dsqlSource = derivedField->dsqlValue;
							else
								castNode->dsqlSource = select_item;

							// When a cast is created we're losing our fieldname, thus
							// create an alias to keep it.
							const dsql_nod* name_node = select_item;
							const DsqlMapNode* mapNode;

							while ((mapNode = ExprNode::as<DsqlMapNode>(name_node)))
							{
								// Skip all the DsqlMapNodes.
								name_node = mapNode->map->map_node;
							}

							const FieldNode* fieldNode;

							if ((fieldNode = ExprNode::as<FieldNode>(name_node)))
							{
								// Create new node for alias and copy fieldname
								alias_node = MAKE_node(nod_alias, e_alias_count);
								// Copy fieldname to a new string.
								dsql_str* str_alias = FB_NEW_RPT(*tdbb->getDefaultPool(),
									fieldNode->dsqlField->fld_name.length()) dsql_str;
								strcpy(str_alias->str_data, fieldNode->dsqlField->fld_name.c_str());
								str_alias->str_length = fieldNode->dsqlField->fld_name.length();
								alias_node->nod_arg[e_alias_alias] = (dsql_nod*) str_alias;
							}
						}

						dsql_fld* field = ExprNode::as<CastNode>(cast_node)->dsqlField;
						// Copy the descriptor to a field, because the gen_cast
						// uses a dsql field type.
						field->fld_dtype = desc.dsc_dtype;
						field->fld_scale = desc.dsc_scale;
						field->fld_sub_type = desc.dsc_sub_type;
						field->fld_length = desc.dsc_length;
						field->fld_flags = (desc.dsc_flags & DSC_nullable) ? FLD_nullable : 0;

						if (desc.dsc_dtype <= dtype_any_text)
						{
							field->fld_ttype = desc.dsc_sub_type;
							field->fld_character_set_id = INTL_GET_CHARSET(&desc);
							field->fld_collation_id = INTL_GET_COLLATE(&desc);
						}
						else if (desc.dsc_dtype == dtype_blob)
						{
							field->fld_character_set_id = desc.dsc_scale;
							field->fld_collation_id = desc.dsc_flags >> 8;
						}

						// Finally copy the descriptors to the root nodes and swap
						// the necessary nodes.
						cast_node->nod_desc = desc;

						if (select_item->nod_desc.dsc_flags & DSC_nullable)
							cast_node->nod_desc.dsc_flags |= DSC_nullable;

						if (select_item->nod_type == nod_alias)
						{
							select_item->nod_arg[e_alias_value] = cast_node;
							select_item->nod_desc = desc;
						}
						else if ((derivedField = ExprNode::as<DerivedFieldNode>(select_item)))
						{
							derivedField->dsqlValue = cast_node;
							select_item->nod_desc = desc;
						}
						else
						{
							// If a new alias was created for keeping original field-name
							// make the alias the "top" node.
							if (alias_node)
							{
								alias_node->nod_arg[e_alias_value] = cast_node;
								alias_node->nod_desc = cast_node->nod_desc;
								input->nod_arg[position] = alias_node;
							}
							else
								input->nod_arg[position] = cast_node;
						}
					}
				}
			}
			else
			{
				dsql_nod** ptr = input->nod_arg;

				for (const dsql_nod* const* const end = ptr + input->nod_count; ptr < end; ptr++)
					pass1_union_auto_cast(dsqlScratch, *ptr, desc, position);
			}
			break;

		case nod_class_exprnode:
		{
			RseNode* rseNode;
			UnionSourceNode* unionNode;

			if ((rseNode = ExprNode::as<RseNode>(input)) && !rseNode->dsqlExplicitJoin)
			{
				pass1_union_auto_cast(dsqlScratch, rseNode->dsqlStreams, desc, position);

				if ((unionNode = ExprNode::as<UnionSourceNode>(rseNode->dsqlStreams)))
				{
					// We're now in a UNION under a UNION so don't change the existing mappings.
					// Only replace the node where the map points to, because they could be changed.
					dsql_nod* sub_rse_items = ExprNode::as<RseNode>(
						unionNode->dsqlClauses->nod_arg[0])->dsqlSelectList;
					dsql_map* map = ExprNode::as<DsqlMapNode>(rseNode->dsqlSelectList->nod_arg[position])->map;
					map->map_node = sub_rse_items->nod_arg[position];
					rseNode->dsqlSelectList->nod_arg[position]->nod_desc = desc;
				}
				else
					pass1_union_auto_cast(dsqlScratch, rseNode->dsqlSelectList, desc, position, true);
			}
			else if ((unionNode = ExprNode::as<UnionSourceNode>(input)))
			{
				dsql_nod** ptr = unionNode->dsqlClauses->nod_arg;

				for (const dsql_nod* const* const end = ptr + unionNode->dsqlClauses->nod_count;
					 ptr != end;
					 ++ptr)
				{
					pass1_union_auto_cast(dsqlScratch, *ptr, desc, position);
				}
			}

			break;
		}
	}
}


/**

 	pass1_update

    @brief	Process UPDATE statement.


    @param dsqlScratch
    @param input

 **/
static dsql_nod* pass1_update(DsqlCompilerScratch* dsqlScratch, dsql_nod* input, bool insert_or_update)
{
	thread_db* tdbb = JRD_get_thread_data();
	MemoryPool& pool = *tdbb->getDefaultPool();

	DEV_BLKCHK(dsqlScratch, dsql_type_req);
	DEV_BLKCHK(input, dsql_type_nod);

	const bool isUpdateSqlCompliant = !Config::getOldSetClauseSemantics();

	// Separate old and new context references

	Firebird::Array<dsql_nod*> org_values, new_values;

	dsql_nod* list = input->nod_arg[e_upd_statement];
	fb_assert(list->nod_type == nod_list);

	for (int i = 0; i < list->nod_count; ++i)
	{
		const dsql_nod* const assign = list->nod_arg[i];
		fb_assert(assign->nod_type == nod_assign);
		org_values.add(assign->nod_arg[e_asgn_value]);
		new_values.add(assign->nod_arg[e_asgn_field]);
	}

	dsql_nod** ptr;

	dsql_nod* cursor = input->nod_arg[e_upd_cursor];
	dsql_nod* relation = input->nod_arg[e_upd_relation];

	if (cursor && dsqlScratch->isPsql())
	{
		dsql_nod* anode = MAKE_node(nod_modify_current, e_mdc_count);
		dsql_ctx* context = pass1_cursor_context(dsqlScratch, cursor, relation);
		anode->nod_arg[e_mdc_context] = (dsql_nod*) context;

		if (isUpdateSqlCompliant)
		{
			// Process old context values
			dsqlScratch->context->push(context);
			dsqlScratch->scopeLevel++;
			for (ptr = org_values.begin(); ptr < org_values.end(); ++ptr)
			{
				*ptr = PASS1_node_psql(dsqlScratch, *ptr, false);
			}
			dsqlScratch->scopeLevel--;
			dsqlScratch->context->pop();
		}

		// Process relation
		anode->nod_arg[e_mdc_update] = PASS1_node_psql(dsqlScratch, relation, false);

		if (!isUpdateSqlCompliant)
		{
			// Process old context values
			for (ptr = org_values.begin(); ptr < org_values.end(); ++ptr)
			{
				*ptr = PASS1_node_psql(dsqlScratch, *ptr, false);
			}
		}

		// Process new context values
		for (ptr = new_values.begin(); ptr < new_values.end(); ++ptr)
		{
			*ptr = PASS1_node_psql(dsqlScratch, *ptr, false);
		}

		anode->nod_arg[e_mdc_return] = process_returning(dsqlScratch, input->nod_arg[e_upd_return]);

		dsqlScratch->context->pop();
		// Recreate list of assignments
		anode->nod_arg[e_mdc_statement] = list = MAKE_node(nod_list, list->nod_count);
		for (int i = 0; i < list->nod_count; ++i)
		{
			dsql_nod* assign = MAKE_node(nod_assign, e_asgn_count);
			assign->nod_arg[e_asgn_value] = org_values[i];
			assign->nod_arg[e_asgn_field] = new_values[i];
			list->nod_arg[i] = assign;
		}
		// We do not allow cases like UPDATE T SET f1 = v1, f2 = v2, f1 = v3...
		field_appears_once(anode->nod_arg[e_mdc_statement],
						   input->nod_arg[e_upd_statement],
						   false, "UPDATE");
		return anode;
	}

	dsqlScratch->getStatement()->setType(
		cursor ? DsqlCompiledStatement::TYPE_UPDATE_CURSOR : DsqlCompiledStatement::TYPE_UPDATE);

	dsql_nod* node = MAKE_node(nod_modify, e_mod_count);
	node->nod_arg[e_mod_update] = PASS1_node_psql(dsqlScratch, relation, false);
	dsql_ctx* mod_context = get_context(node->nod_arg[e_mod_update]);

	if (!isUpdateSqlCompliant)
	{
		// Process old context values
		for (ptr = org_values.begin(); ptr < org_values.end(); ++ptr)
			*ptr = PASS1_node_psql(dsqlScratch, *ptr, false);
	}

	// Process new context values
	for (ptr = new_values.begin(); ptr < new_values.end(); ++ptr)
		*ptr = PASS1_node_psql(dsqlScratch, *ptr, false);

	dsqlScratch->context->pop();

	// Generate record selection expression

	dsql_nod* rseNod;

	if (cursor)
		rseNod = pass1_cursor_reference(dsqlScratch, cursor, relation);
	else
	{
		RseNode* rse = FB_NEW(pool) RseNode(pool);

		rseNod = MAKE_node(nod_class_exprnode, 1);
		rseNod->nod_arg[0] = reinterpret_cast<dsql_nod*>(rse);
		rseNod->nod_flags = (USHORT)(IPTR) input->nod_arg[e_upd_rse_flags];

		if (input->nod_arg[e_upd_return])
			rseNod->nod_flags |= NOD_SELECT_EXPR_SINGLETON;

		dsql_nod* temp = MAKE_node(nod_list, 1);
		rse->dsqlStreams = temp;
		temp->nod_arg[0] = PASS1_node_psql(dsqlScratch, relation, false);
		dsql_ctx* old_context = get_context(temp->nod_arg[0]);

		if ((temp = input->nod_arg[e_upd_boolean]))
			rse->dsqlWhere = PASS1_node_psql(dsqlScratch, temp, false);

		if ((temp = input->nod_arg[e_upd_plan]))
			rse->dsqlPlan = PASS1_node_psql(dsqlScratch, temp, false);

		if ((temp = input->nod_arg[e_upd_sort]))
			rse->dsqlOrder = pass1_sort(dsqlScratch, temp, NULL);

		if ((temp = input->nod_arg[e_upd_rows]))
			pass1_limit(dsqlScratch, temp->nod_arg[e_rows_length], temp->nod_arg[e_rows_skip], rse);

		if (input->nod_arg[e_upd_return])
		{
			node->nod_arg[e_mod_return] = ReturningProcessor(
				dsqlScratch, old_context, mod_context).process(input->nod_arg[e_upd_return]);
		}
	}

	node->nod_arg[e_mod_source] = ExprNode::as<RseNode>(rseNod)->dsqlStreams->nod_arg[0];
	node->nod_arg[e_mod_rse] = rseNod;

	if (isUpdateSqlCompliant)
	{
		// Process old context values
		for (ptr = org_values.begin(); ptr < org_values.end(); ++ptr)
		{
			*ptr = PASS1_node_psql(dsqlScratch, *ptr, false);
		}
	}

	dsqlScratch->context->pop();

	// Recreate list of assignments
	node->nod_arg[e_mod_statement] = list = MAKE_node(nod_list, list->nod_count);

	for (int j = 0; j < list->nod_count; ++j)
	{
		dsql_nod* const sub1 = org_values[j];
		dsql_nod* const sub2 = new_values[j];
		if (!PASS1_set_parameter_type(dsqlScratch, sub1, sub2, false))
		{
			PASS1_set_parameter_type(dsqlScratch, sub2, sub1, false);
		}
		dsql_nod* assign = MAKE_node(nod_assign, e_asgn_count);
		assign->nod_arg[e_asgn_value] = sub1;
		assign->nod_arg[e_asgn_field] = sub2;
		list->nod_arg[j] = assign;
	}

	// We do not allow cases like UPDATE T SET f1 = v1, f2 = v2, f1 = v3...
	field_appears_once(node->nod_arg[e_mod_statement],
					   input->nod_arg[e_upd_statement],
					   false, "UPDATE");

	set_parameters_name(node->nod_arg[e_mod_statement], node->nod_arg[e_mod_update]);

	if (!insert_or_update)
		nullify_returning(dsqlScratch, node, &node);

	return node;
}


/**

 	pass1_update_or_insert

    @brief	Process UPDATE OR INSERT statement.


    @param dsqlScratch
    @param input

 **/
static dsql_nod* pass1_update_or_insert(DsqlCompilerScratch* dsqlScratch, dsql_nod* input)
{
	DEV_BLKCHK(dsqlScratch, dsql_type_req);
	DEV_BLKCHK(input, dsql_type_nod);

	thread_db* tdbb = JRD_get_thread_data();
	MemoryPool& pool = *tdbb->getDefaultPool();

	if (!dsqlScratch->isPsql())
		dsqlScratch->flags |= DsqlCompilerScratch::FLAG_UPDATE_OR_INSERT;

	const MetaName& relation_name = ExprNode::as<RelationSourceNode>(input->nod_arg[e_upi_relation])->dsqlName;
	MetaName base_name = relation_name;

	dsql_nod* values = input->nod_arg[e_upi_values];

	// build the INSERT node
	dsql_nod* insert = MAKE_node(nod_insert, e_ins_count);
	insert->nod_arg[e_ins_relation] = input->nod_arg[e_upi_relation];
	insert->nod_arg[e_ins_fields] = input->nod_arg[e_upi_fields];
	insert->nod_arg[e_ins_values] = values;
	insert->nod_arg[e_ins_return] = input->nod_arg[e_upi_return];
	insert = pass1_insert(dsqlScratch, insert, true);

	// PASS1_statement will transform nod_insert to nod_store
	fb_assert(insert->nod_type == nod_store);

	dsql_ctx* context = ExprNode::as<RelationSourceNode>(insert->nod_arg[e_sto_relation])->dsqlContext;
	DEV_BLKCHK(context, dsql_type_ctx);

	dsql_rel* relation = context->ctx_relation;
	dsql_nod* fields = input->nod_arg[e_upi_fields];

	// if a field list isn't present, build one using the same
	// rules of INSERT INTO table VALUES ...
	if (!fields)
		fields = explode_fields(relation);

	// maintain a pair of view's field name / base field name
	MetaNamePairMap view_fields;

	if ((relation->rel_flags & REL_view) && !input->nod_arg[e_upi_matching])
	{
		dsql_rel* base_rel = METD_get_view_base(dsqlScratch->getTransaction(), dsqlScratch,
			relation_name.c_str(), view_fields);

		// get the base table name if there is only one
		if (base_rel)
			base_name = base_rel->rel_name;
		else
			ERRD_post(Arg::Gds(isc_upd_ins_with_complex_view));
	}

	dsql_nod* matching = input->nod_arg[e_upi_matching];
	UCHAR equality_type;

	if (matching)
	{
		equality_type = blr_equiv;

		dsqlScratch->context->push(context);
		dsqlScratch->scopeLevel++;

		const dsql_nod* matching_fields = PASS1_node_psql(dsqlScratch, matching, false);

		dsqlScratch->scopeLevel--;
		dsqlScratch->context->pop();

		field_appears_once(matching_fields, matching, true, "UPDATE OR INSERT");
	}
	else
	{
		equality_type = blr_eql;

		matching = METD_get_primary_key(dsqlScratch->getTransaction(), base_name.c_str());

		if (!matching)
			ERRD_post(Arg::Gds(isc_primary_key_required) << base_name);
	}

	// build a boolean to use in the UPDATE dsqlScratch
	dsql_nod* match = NULL;
	USHORT match_count = 0;

	DsqlNodStack varStack;

	DsqlNodStack stack;
	dsql_nod** field_ptr = fields->nod_arg;
	dsql_nod** value_ptr = values->nod_arg;

	for (const dsql_nod* const* const field_end = field_ptr + fields->nod_count;
		 field_ptr < field_end; field_ptr++, value_ptr++)
	{
		DEV_BLKCHK(*field_ptr, dsql_type_nod);
		DEV_BLKCHK(*value_ptr, dsql_type_nod);

		dsql_nod* assign = MAKE_node(nod_assign, e_asgn_count);
		assign->nod_arg[e_asgn_value] = *value_ptr;
		assign->nod_arg[e_asgn_field] = *field_ptr;
		stack.push(assign);

		dsql_nod* temp = *value_ptr;
		dsql_nod* temp2 = insert->nod_arg[e_sto_statement]->nod_arg[field_ptr - fields->nod_arg]->nod_arg[1];
		PASS1_set_parameter_type(dsqlScratch, temp, temp2, false);

		fb_assert((*field_ptr)->nod_type == nod_field_name);

		// When relation is a view and MATCHING was not specified, field_name
		// stores the base field name that is what we should find in the primary
		// key of base table.
		Firebird::MetaName field_name;

		if ((relation->rel_flags & REL_view) && !input->nod_arg[e_upi_matching])
		{
			view_fields.get(
				Firebird::MetaName(((dsql_str*) (*field_ptr)->nod_arg[e_fln_name])->str_data),
				field_name);
		}
		else
			field_name = ((dsql_str*) (*field_ptr)->nod_arg[e_fln_name])->str_data;

		if (field_name.hasData())
		{
			dsql_nod** matching_ptr = matching->nod_arg;

			for (const dsql_nod* const* const matching_end = matching_ptr + matching->nod_count;
				 matching_ptr < matching_end; matching_ptr++)
			{
				DEV_BLKCHK(*matching_ptr, dsql_type_nod);
				fb_assert((*matching_ptr)->nod_type == nod_field_name);

				const Firebird::MetaName
					testField(((dsql_str*)(*matching_ptr)->nod_arg[e_fln_name])->str_data);

				if (testField == field_name)
				{
					++match_count;

					const size_t fieldPos = field_ptr - fields->nod_arg;
					dsql_nod*& expr = insert->nod_arg[e_sto_statement]->nod_arg[fieldPos]->nod_arg[0];
					dsql_nod* var = pass1_hidden_variable(dsqlScratch, expr);

					if (var)
					{
						dsql_nod* varAssign = MAKE_node(nod_assign, e_asgn_count);
						varAssign->nod_arg[e_asgn_value] = expr;
						varAssign->nod_arg[e_asgn_field] = var;
						varStack.push(varAssign);

						assign->nod_arg[e_asgn_value] = expr = var;
					}
					else
						var = *value_ptr;

					ComparativeBoolNode* eqlNode = FB_NEW(pool) ComparativeBoolNode(pool,
						equality_type, *field_ptr, var);

					dsql_nod* eqlNod = MAKE_node(nod_class_exprnode, 1);
					eqlNod->nod_arg[0] = reinterpret_cast<dsql_nod*>(eqlNode);

					match = PASS1_compose(match, eqlNod, blr_and);
				}
			}
		}
	}

	// check if implicit or explicit MATCHING is valid
	if (match_count != matching->nod_count)
	{
		if (input->nod_arg[e_upi_matching])
			ERRD_post(Arg::Gds(isc_upd_ins_doesnt_match_matching));
		else
			ERRD_post(Arg::Gds(isc_upd_ins_doesnt_match_pk) << base_name);
	}

	// build the UPDATE node
	dsql_nod* update = MAKE_node(nod_update, e_upd_count);
	update->nod_arg[e_upd_relation] = input->nod_arg[e_upi_relation];
	update->nod_arg[e_upd_statement] = MAKE_list(stack);
	update->nod_arg[e_upd_boolean] = match;

	if (input->nod_arg[e_upi_return])
	{
		update->nod_arg[e_upd_rse_flags] = (dsql_nod*)(IPTR) NOD_SELECT_EXPR_SINGLETON;
		update->nod_arg[e_upd_return] = ReturningProcessor::clone(
			input->nod_arg[e_upi_return], insert->nod_arg[e_sto_return]);
	}

	update = pass1_update(dsqlScratch, update, true);

	// PASS1_statement will transform nod_update to nod_modify
	fb_assert(update->nod_type == nod_modify);

	// test if ROW_COUNT = 0

	ComparativeBoolNode* eqlNode = FB_NEW(pool) ComparativeBoolNode(pool,
		blr_eql, MAKE_node(nod_class_exprnode, 1), MAKE_const_slong(0));

	eqlNode->dsqlArg1->nod_arg[0] = reinterpret_cast<dsql_nod*>(FB_NEW(pool) InternalInfoNode(pool,
		MAKE_const_slong(SLONG(InternalInfoNode::INFO_TYPE_ROWS_AFFECTED))));

	dsql_nod* eqlNod = MAKE_node(nod_class_exprnode, 1);
	eqlNod->nod_arg[0] = reinterpret_cast<dsql_nod*>(eqlNode);

	const ULONG save_flags = dsqlScratch->flags;
	dsqlScratch->flags |= DsqlCompilerScratch::FLAG_BLOCK;	// to compile ROW_COUNT
	eqlNod = PASS1_node(dsqlScratch, eqlNod);
	dsqlScratch->flags = save_flags;

	// if (ROW_COUNT = 0) then INSERT
	IfNode* ifNode = FB_NEW(pool) IfNode(pool);
	ifNode->dsqlCondition = eqlNod;
	ifNode->dsqlTrueAction = insert;

	// build the temporary vars / UPDATE / IF nodes
	dsql_nod* list = MAKE_node(nod_list, 3);
	list->nod_arg[0] = MAKE_list(varStack);
	list->nod_arg[0]->nod_flags |= NOD_SIMPLE_LIST;
	list->nod_arg[1] = update;
	list->nod_arg[2] = MAKE_node(nod_class_stmtnode, 1);
	list->nod_arg[2]->nod_arg[0] = (dsql_nod*) ifNode;

	// if RETURNING is present, type is already DsqlCompiledStatement::TYPE_EXEC_PROCEDURE
	if (!input->nod_arg[e_upi_return])
		dsqlScratch->getStatement()->setType(DsqlCompiledStatement::TYPE_INSERT);

	return list;
}


/**

 	pass1_variable

    @brief	Resolve a variable name to an available variable.


    @param dsqlScratch
    @param input

 **/
static dsql_nod* pass1_variable(DsqlCompilerScratch* dsqlScratch, dsql_nod* input)
{
	thread_db* tdbb = JRD_get_thread_data();

	// CVC: I commented this variable and its usage because it wasn't useful for
	// anything. I didn't delete it in case it's an implementation in progress
	// by someone.
	//SSHORT position;

	DEV_BLKCHK(dsqlScratch, dsql_type_req);
	DEV_BLKCHK(input, dsql_type_nod);

	const dsql_str* var_name = NULL;

	if (input->nod_type == nod_field_name)
	{
		if (input->nod_arg[e_fln_context])
		{
			if (dsqlScratch->flags & DsqlCompilerScratch::FLAG_TRIGGER) // triggers only
				return pass1_field(dsqlScratch, input, false, NULL);

			PASS1_field_unknown(NULL, NULL, input);
		}

		var_name = (dsql_str*) input->nod_arg[e_fln_name];
	}
	else
		var_name = (dsql_str*) input->nod_arg[e_vrn_name];

	DEV_BLKCHK(var_name, dsql_type_str);

	dsql_var* variable = dsqlScratch->resolveVariable(var_name);

	if (variable)
	{
		VariableNode* varNode = FB_NEW(*tdbb->getDefaultPool()) VariableNode(*tdbb->getDefaultPool());
		varNode->dsqlVar = variable;

		dsql_nod* node = MAKE_node(nod_class_exprnode, 1);
		node->nod_arg[0] = reinterpret_cast<dsql_nod*>(varNode);
		return node;
	}

	// field unresolved
	// CVC: That's all [the fix], folks!

	if (var_name)
		PASS1_field_unknown(NULL, var_name->str_data, input);
	else
		PASS1_field_unknown(NULL, NULL, input);

	return NULL;
}


// Post an item to a map for a context.
dsql_nod* PASS1_post_map(DsqlCompilerScratch* dsqlScratch, ValueExprNode* node, dsql_ctx* context,
	dsql_nod* partitionNode, dsql_nod* orderNode)
{
    dsql_nod* nod = MAKE_node(nod_class_exprnode, 1);
    nod->nod_arg[0] = reinterpret_cast<dsql_nod*>(node);
    return PASS1_post_map(dsqlScratch, nod, context, partitionNode, orderNode);
}

// Post an item to a map for a context.
dsql_nod* PASS1_post_map(DsqlCompilerScratch* dsqlScratch, dsql_nod* node, dsql_ctx* context,
	dsql_nod* partitionNode, dsql_nod* orderNode)
{
	DEV_BLKCHK(node, dsql_type_nod);
	DEV_BLKCHK(context, dsql_type_ctx);

	thread_db* tdbb = JRD_get_thread_data();

	PartitionMap* partitionMap = NULL;
	dsql_map* map = NULL;

	if (dsqlScratch->processingWindow)
	{
		partitionMap = context->getPartitionMap(dsqlScratch, partitionNode, orderNode);
		map = partitionMap->map;
	}
	else
		map = context->ctx_map;

	USHORT count = 0;

	while (map)
	{
		if (PASS1_node_match(node, map->map_node, false))
			break;

		++count;
		map = map->map_next;
	}

	if (!map)
	{
		dsql_map** next = partitionMap ? &partitionMap->map : &context->ctx_map;

		if (*next)
		{
			while (*(next = &(*next)->map_next))
				;
		}

		map = *next = FB_NEW(*tdbb->getDefaultPool()) dsql_map;
		map->map_position = count;
		map->map_node = node;
		map->map_partition = partitionMap;
	}

	MAKE_desc(dsqlScratch, &node->nod_desc, node);

	DsqlMapNode* mapNode = FB_NEW(*tdbb->getDefaultPool()) DsqlMapNode(*tdbb->getDefaultPool(),
		context, map);

    dsql_nod* new_node = MAKE_node(nod_class_exprnode, 1);
    new_node->nod_arg[0] = reinterpret_cast<dsql_nod*>(mapNode);
	new_node->nod_desc = node->nod_desc;

	return new_node;
}


/**

 remap_streams_to_parent_context

    @brief	For each relation in the list, flag the relation's context
 	as having a parent context.  Be sure to handle joins
 	(Bug 6674).


    @param input
    @param parent_context

 **/
static void remap_streams_to_parent_context( dsql_nod* input, dsql_ctx* parent_context)
{
	DEV_BLKCHK(input, dsql_type_nod);
	DEV_BLKCHK(parent_context, dsql_type_ctx);

	switch (input->nod_type)
	{
	case nod_list:
		{
			dsql_nod** ptr = input->nod_arg;
			for (const dsql_nod* const* const end = ptr + input->nod_count; ptr < end; ptr++)
				remap_streams_to_parent_context(*ptr, parent_context);
		}
		break;

	default:
		{
			ProcedureSourceNode* procNode;
			RelationSourceNode* relNode;
			RseNode* rseNode;
			UnionSourceNode* unionNode;

			if ((procNode = ExprNode::as<ProcedureSourceNode>(input)))
			{
				DEV_BLKCHK(procNode->dsqlContext, dsql_type_ctx);
				procNode->dsqlContext->ctx_parent = parent_context;
			}
			else if ((relNode = ExprNode::as<RelationSourceNode>(input)))
			{
				DEV_BLKCHK(relNode->dsqlContext, dsql_type_ctx);
				relNode->dsqlContext->ctx_parent = parent_context;
			}
			else if ((rseNode = ExprNode::as<RseNode>(input)))
				remap_streams_to_parent_context(rseNode->dsqlStreams, parent_context);
			else if ((unionNode = ExprNode::as<UnionSourceNode>(input)))
			{
				dsql_nod** rse = unionNode->dsqlClauses->nod_arg;
				for (const dsql_nod* const* const end = rse + unionNode->dsqlClauses->nod_count; rse != end; ++rse)
					remap_streams_to_parent_context(ExprNode::as<RseNode>(*rse)->dsqlStreams, parent_context);
			}
			else if (!ExprNode::as<AggregateSourceNode>(input))
			{
				fb_assert(false);
			}
		}
		break;
	}
}


/**

 	resolve_context

    @brief	Attempt to resolve field against context.
 	Return first field in context if successful,
 	NULL if not.


    @param dsqlScratch
    @param name
    @param qualifier
    @param context

 **/
static dsql_fld* resolve_context( DsqlCompilerScratch* dsqlScratch, const dsql_str* qualifier,
	dsql_ctx* context, bool resolveByAlias)
{
	// CVC: Warning: the second param, "name" was is not used anymore and
	// therefore it was removed. Thus, the local variable "table_name"
	// is being stripped here to avoid mismatches due to trailing blanks.

	DEV_BLKCHK(dsqlScratch, dsql_type_req);
	DEV_BLKCHK(qualifier, dsql_type_str);
	DEV_BLKCHK(context, dsql_type_ctx);

	if ((dsqlScratch->flags & DsqlCompilerScratch::FLAG_RETURNING_INTO) &&
		(context->ctx_flags & CTX_returning))
	{
		return NULL;
	}

	dsql_rel* relation = context->ctx_relation;
	dsql_prc* procedure = context->ctx_procedure;
	if (!relation && !procedure) {
		return NULL;
	}

	// if there is no qualifier, then we cannot match against
	// a context of a different scoping level
	// AB: Yes we can, but the scope level where the field is has priority.
//	if (!qualifier && context->ctx_scope_level != dsqlScratch->scopeLevel) {
//		return NULL;
//	}

	// AB: If this context is a system generated context as in NEW/OLD inside
	// triggers, the qualifier by the field is mandatory. While we can't
	// fall back from a higher scope-level to the NEW/OLD contexts without
	// the qualifier present.
	// An exception is a check-constraint that is allowed to reference fields
	// without the qualifier.
	if (!dsqlScratch->checkConstraintTrigger && (context->ctx_flags & CTX_system) && !qualifier) {
		return NULL;
	}

	const TEXT* table_name = NULL;
	if (context->ctx_internal_alias.hasData() && resolveByAlias)
		table_name = context->ctx_internal_alias.c_str();

	// AB: For a check constraint we should ignore the alias if the alias
	// contains the "NEW" alias. This is because it is possible
	// to reference a field by the complete table-name as alias
	// (see EMPLOYEE table in examples for a example).
	if (dsqlScratch->checkConstraintTrigger && table_name)
	{
		// If a qualifier is present and it's equal to the alias then we've already the right table-name
		if (!(qualifier && !strcmp(qualifier->str_data, table_name)))
		{
			if (strcmp(table_name, NEW_CONTEXT) == 0)
				table_name = NULL;
			else if (strcmp(table_name, OLD_CONTEXT) == 0)
			{
				// Only use the OLD context if it is explicit used. That means the
				// qualifer should hold the "OLD" alias.
				return NULL;
			}
		}
	}

	if (!table_name)
	{
		if (relation)
			table_name = relation->rel_name.c_str();
		else
			table_name = procedure->prc_name.identifier.c_str();
	}

	// If a context qualifier is present, make sure this is the proper context
	if (qualifier && strcmp(qualifier->str_data, table_name) != 0)
		return NULL;

	// Lookup field in relation or procedure

	return relation ? relation->rel_fields : procedure->prc_outputs;
}


/**

 	PASS1_set_parameter_type

    @brief	Setup the datatype of a parameter.


    @param in_node
    @param node
    @param force_varchar

 **/
bool PASS1_set_parameter_type(DsqlCompilerScratch* dsqlScratch, dsql_nod* in_node,
	dsql_nod* node, bool force_varchar)
{
	thread_db* tdbb = JRD_get_thread_data();

	DEV_BLKCHK(in_node, dsql_type_nod);
	DEV_BLKCHK(node, dsql_type_nod);

	if (!in_node || in_node->nod_type != nod_class_exprnode)
		return false;

	ValueExprNode* exprNode = reinterpret_cast<ValueExprNode*>(in_node->nod_arg[0]);
	if (exprNode->kind == DmlNode::KIND_VALUE)
		return exprNode->setParameterType(dsqlScratch, node, force_varchar);
	else
		return false;
}


/**

 set_parameters_name

    @brief      Setup parameter parameters name.


    @param list_node
    @param rel_node

 **/
static void set_parameters_name( dsql_nod* list_node, const dsql_nod* rel_node)
{
	DEV_BLKCHK(list_node, dsql_type_nod);
	DEV_BLKCHK(rel_node, dsql_type_nod);

	const dsql_ctx* context = ExprNode::as<RelationSourceNode>(rel_node)->dsqlContext;
	DEV_BLKCHK(context, dsql_type_ctx);
	const dsql_rel* relation = context->ctx_relation;

	dsql_nod** ptr = list_node->nod_arg;
	for (const dsql_nod* const* const end = ptr + list_node->nod_count; ptr < end; ptr++)
	{
		DEV_BLKCHK(*ptr, dsql_type_nod);
		if ((*ptr)->nod_type == nod_assign)
			set_parameter_name((*ptr)->nod_arg[e_asgn_value], (*ptr)->nod_arg[e_asgn_field], relation);
		else
			fb_assert(FALSE);
	}
}


/**

 set_parameter_name

	@brief      Setup parameter parameter name.
	This function was added as a part of array data type
	support for InterClient. It is	called when either
	"insert" or "update" statements are parsed. If the
	statements have input parameters, than the parameter
	is assigned the name of the field it is being inserted
	(or updated). The same goes to the name of a relation.
	The names are assigned to the parameter only if the
	field is of array data type.


    @param par_node
    @param fld_node
    @param relation

 **/
static void set_parameter_name( dsql_nod* par_node, const dsql_nod* fld_node, const dsql_rel* relation)
{
	DEV_BLKCHK(par_node, dsql_type_nod);
	DEV_BLKCHK(fld_node, dsql_type_nod);
	DEV_BLKCHK(relation, dsql_type_dsql_rel);

	if (!par_node)
		return;

	const FieldNode* fieldNode = ExprNode::as<FieldNode>(fld_node);
	fb_assert(fieldNode);	// Could it be something else ???

	if (fieldNode->dsqlDesc.dsc_dtype != dtype_array)
		return;

	switch (par_node->nod_type)
	{
	case nod_class_exprnode:
		{
			ExprNode* exprNode = reinterpret_cast<ExprNode*>(par_node->nod_arg[0]);

			switch (exprNode->type)
			{
				case ExprNode::TYPE_ARITHMETIC:
				case ExprNode::TYPE_CONCATENATE:
				case ExprNode::TYPE_EXTRACT:
				case ExprNode::TYPE_NEGATE:
				case ExprNode::TYPE_STR_CASE:
				case ExprNode::TYPE_STR_LEN:
				case ExprNode::TYPE_SUBSTRING:
				case ExprNode::TYPE_SUBSTRING_SIMILAR:
				case ExprNode::TYPE_TRIM:
					for (dsql_nod*** i = exprNode->dsqlChildNodes.begin();
						 i != exprNode->dsqlChildNodes.end(); ++i)
					{
						set_parameter_name(**i, fld_node, relation);
					}
					break;

				case ExprNode::TYPE_PARAMETER:
				{
					ParameterNode* paramNode = exprNode->as<ParameterNode>();
					dsql_par* parameter = paramNode->dsqlParameter;
					parameter->par_name = fieldNode->dsqlField->fld_name.c_str();
					parameter->par_rel_name = relation->rel_name.c_str();
					break;
				}
			}
		}
		return;

	default:
		return;
	}
}


/**

 pass1_savepoint

    @brief      Add savepoint pair of nodes
				to statement having error handlers.


    @param dsqlScratch
	@param node

 **/
static dsql_nod* pass1_savepoint(const DsqlCompilerScratch* dsqlScratch, dsql_nod* node)
{
	if (dsqlScratch->errorHandlers)
	{
		dsql_nod* temp = MAKE_node(nod_list, 3);
		temp->nod_arg[0] = MAKE_node(nod_start_savepoint, 0);
		temp->nod_arg[1] = node;
		temp->nod_arg[2] = MAKE_node(nod_end_savepoint, 0);
		node = temp;
	}

	return node;
}


// Returns false for hidden fields and true for non-hidden.
// For non-hidden, change "node" if the field is part of an
// implicit join.
bool dsql_ctx::getImplicitJoinField(const Firebird::MetaName& name, dsql_nod*& node)
{
	ImplicitJoin* impJoin;
	if (ctx_imp_join.get(name, impJoin))
	{
		if (impJoin->visibleInContext == this)
		{
			node = impJoin->value;
			return true;
		}

		return false;
	}

	return true;
}

// Returns (creating, if necessary) the PartitionMap of a given partition (that may be NULL).
PartitionMap* dsql_ctx::getPartitionMap(DsqlCompilerScratch* dsqlScratch, dsql_nod* partitionNode,
	dsql_nod* orderNode)
{
	thread_db* tdbb = JRD_get_thread_data();

	PartitionMap* partitionMap = NULL;

	for (Array<PartitionMap*>::iterator i = ctx_win_maps.begin();
		 !partitionMap && i != ctx_win_maps.end();
		 ++i)
	{
		if (PASS1_node_match((*i)->partition, partitionNode, false) &&
			PASS1_node_match((*i)->order, orderNode, false))
		{
			partitionMap = *i;
		}
	}

	if (!partitionMap)
	{
		partitionMap = FB_NEW(*tdbb->getDefaultPool()) PartitionMap(partitionNode, orderNode);
		ctx_win_maps.add(partitionMap);
		partitionMap->context = dsqlScratch->contextNumber++;
	}

	return partitionMap;
}

#ifdef DSQL_DEBUG

#include <stdarg.h>

static void trace_line(const char* message, ...)
{
	char buffer[1024];
	va_list params;
	va_start(params, message);
	VSNPRINTF(buffer, sizeof(buffer), message, params);
	va_end(params);
	buffer[sizeof(buffer) - 1] = 0;
	gds__trace_raw(buffer);
}

/**

 	DSQL_pretty

    @brief	Pretty print a node tree.


    @param node
    @param column

 **/
void DSQL_pretty(const dsql_nod* node, int column)
{
	TEXT buffer[1024];

	TEXT* p = buffer;
	p += sprintf(p, "%p ", (void*) node);

	if (column)
	{
		USHORT l = column * 3;
		do {
			*p++ = ' ';
		} while (--l);
	}

	*p = 0;

	if (!node)
	{
		trace_line("%s *** null ***\n", buffer);
		return;
	}

	switch (node->getType())
	{
	case dsql_type_str:
		trace_line("%sSTRING: \"%s\"\n", buffer, ((dsql_str*) node)->str_data);
		return;

	case dsql_type_fld:
		trace_line("%sFIELD: %s\n", buffer, ((dsql_fld*) node)->fld_name.c_str());
		return;

	case dsql_type_sym:
		trace_line("%sSYMBOL: %s\n", buffer, ((dsql_sym*) node)->sym_string);
		return;

	case dsql_type_nod:
		break;

	default:
		trace_line("%sUNKNOWN BLOCK TYPE\n", buffer);
		return;
	}

	TEXT s[64];
	const dsql_str* string;
	Firebird::string verb;
	const dsql_nod* const* ptr = node->nod_arg;
	const dsql_nod* const* end = ptr + node->nod_count;
	Firebird::Array<dsql_nod*> subNodes;

	switch (node->nod_type)
	{
	case nod_alias:
		verb = "alias";
		break;
	case nod_all:
		verb = "all";
		break;
	case nod_array:
		verb = "array element";
		break;
	case nod_assign:
		verb = "assign";
		break;
	case nod_collate:
		verb = "collate";
		break;
	case nod_cursor:
		verb = "cursor";
		break;
	case nod_def_database:
		verb = "define database";
		break;
	case nod_def_field:
		verb = "define field";
		break;
	case nod_def_filter:
		verb = "define filter";
		break;
	case nod_def_index:
		verb = "define index";
		break;
	case nod_delete:
		verb = "delete";
		break;
	case nod_del_field:
		verb = "delete field";
		break;
	case nod_del_filter:
		verb = "delete filter";
		break;
	case nod_del_generator:
		verb = "delete generator";
		break;
	case nod_del_index:
		verb = "delete index";
		break;
	case nod_erase:
		verb = "erase";
		break;
	case nod_execute:
		verb = "execute";
		break;
	case nod_flag:
		verb = "flag";
		break;
	case nod_foreign:
		verb = "foreign key";
		break;
	case nod_get_segment:
		verb = "get segment";
		break;
	case nod_grant:
		verb = "grant";
		break;
	case nod_insert:
		verb = "insert";
		break;
	case nod_list:
		verb = "list";
		break;
	case nod_modify:
		verb = "modify";
		break;
	case nod_mod_database:
		verb = "modify database";
		break;
	case nod_mod_field:
		verb = "modify field";
		break;
	case nod_order:
		verb = "order";
		break;
	case nod_primary:
		verb = "primary key";
		break;
	case nod_procedure_name:
		verb = "procedure name";
		break;
	case nod_package_name:
		verb = "package name";
		break;
	case nod_function_name:
		verb = "function_name";
		break;
	case nod_put_segment:
		verb = "put segment";
		break;
	case nod_revoke:
		verb = "revoke";
		break;
	case nod_select:
		verb = "select";
		break;
	case nod_select_expr:
		verb = "select expr";
		break;
	case nod_store:
		verb = "store";
		break;
	case nod_update:
		verb = "update";
		break;
	case nod_unique:
		verb = "unique";
		break;

	case nod_rows:
		verb = "rows";
		break;
	// IOL: missing node types
	case nod_on_error:
		verb = "on error";
		break;
	case nod_block:
		verb = "block";
		break;
	case nod_default:
		verb = "default";
		break;
	case nod_plan_expr:
		verb = "plan";
		break;
	case nod_index:
		verb = "index";
		break;
	case nod_index_order:
		verb = "order";
		break;
	case nod_plan_item:
		verb = "item";
		break;
	case nod_natural:
		verb = "natural";
		break;
	// SKIDDER: some more missing node types
	case nod_commit:
		verb = "commit";
		break;
	case nod_rollback:
		verb = "rollback";
		break;
	case nod_trans:
		verb = "trans";
		break;
	case nod_def_default:
		verb = "def_default";
		break;
	case nod_del_default:
		verb = "del_default";
		break;
	case nod_def_domain:
		verb = "def_domain";
		break;
	case nod_def_constraint:
		verb = "def_constraint";
		break;
/*
	case nod_def_trigger_msg:
		verb = "def_trigger_msg";
		break;
	case nod_mod_trigger_msg:
		verb = "mod_trigger_msg";
		break;
	case nod_del_trigger_msg:
		verb = "del_trigger_msg";
		break;
*/
	case nod_def_shadow:
		verb = "def_shadow";
		break;
	case nod_del_shadow:
		verb = "del_shadow";
		break;
	case nod_def_udf:
		verb = "def_udf";
		break;
	case nod_del_udf:
		verb = "del_udf";
		break;
	case nod_rel_constraint:
		verb = "rel_constraint";
		break;
	case nod_delete_rel_constraint:
		verb = "delete_rel_constraint";
		break;
	case nod_references:
		verb = "references";
		break;
	case nod_proc_obj:
		verb = "proc_obj";
		break;
	case nod_func_obj:
		verb = "func_obj";
		break;
	case nod_trig_obj:
		verb = "trig_obj";
		break;
	case nod_view_obj:
		verb = "view_obj";
		break;
	case nod_erase_current:
		verb = "erase_current";
		break;
	case nod_modify_current:
		verb = "modify_current";
		break;
	case nod_sqlcode:
		verb = "sqlcode";
		break;
	case nod_gdscode:
		verb = "gdscode";
		break;
	case nod_exception:
		verb = "exception";
		break;
	case nod_start_savepoint:
		verb = "start_savepoint";
		break;
	case nod_end_savepoint:
		verb = "end_savepoint";
		break;
	case nod_user_group:
		verb = "user_group";
		break;
	case nod_access:
		verb = "access";
		break;
	case nod_wait:
		verb = "wait";
		break;
	case nod_isolation:
		verb = "isolation";
		break;
	case nod_version:
		verb = "version";
		break;
	case nod_table_lock:
		verb = "table_lock";
		break;
	case nod_lock_mode:
		verb = "lock_mode";
		break;
	case nod_reserve:
		verb = "reserve";
		break;
	case nod_retain:
		verb = "retain";
		break;
	case nod_page_size:
		verb = "page_size";
		break;
	case nod_file_length:
		verb = "file_length";
		break;
	case nod_file_desc:
		verb = "file_desc";
		break;
	case nod_dfl_charset:
		verb = "dfl_charset";
		break;
	case nod_password:
		verb = "password";
		break;
	case nod_lc_ctype:
		verb = "lc_ctype";
		break;
	case nod_udf_return_value:
		verb = "udf_return_value";
		break;
	case nod_def_computed:
		verb = "def_computed";
		break;
	case nod_set_generator:
		verb = "set_generator";
		break;
	case nod_set_generator2:
		verb = "set_generator2";
		break;
	case nod_mod_index:
		verb = "mod_index";
		break;
	case nod_idx_active:
		verb = "idx_active";
		break;
	case nod_idx_inactive:
		verb = "idx_inactive";
		break;
	case nod_restrict:
		verb = "restrict";
		break;
	case nod_cascade:
		verb = "cascade";
		break;
	case nod_set_statistics:
		verb = "set_statistics";
		break;
	case nod_ref_upd_del:
		verb = "ref_upd_del";
		break;
	case nod_ref_trig_action:
		verb = "ref_trig_action";
		break;
	case nod_def_role:
		verb = "def_role";
		break;
	case nod_role_name:
		verb = "role_name";
		break;
	case nod_grant_admin:
		verb = "grant_admin";
		break;
	case nod_del_role:
		verb = "del_role";
		break;
	case nod_mod_field_name:
		verb = "mod_field_name";
		break;
	case nod_mod_field_type:
		verb = "mod_field_type";
		break;
	case nod_mod_field_pos:
		verb = "mod_field_pos";
		break;
	case nod_udf_param:
		verb = "udf_param";
		break;
	case nod_for_update:
		verb = "for_update";
		break;
	case nod_difference_file:
		verb = "difference_file";
		break;
	case nod_drop_difference:
		verb = "drop_difference";
		break;
	case nod_begin_backup:
		verb = "begin_backup";
		break;
	case nod_end_backup:
		verb = "end_backup";
		break;

	case nod_while:
		verb = "while";
		break;

	case nod_label:
		verb = "label";
		DSQL_pretty(node->nod_arg[e_label_name], column + 1);
		trace_line("%s   number %d\n", buffer,
			(int)(IPTR)node->nod_arg[e_label_number]);
		return;

	case nod_field_name:
		trace_line("%sfield name: \"", buffer);
		string = (dsql_str*) node->nod_arg[e_fln_context];
		if (string)
			trace_line("%s.", string->str_data);
		string = (dsql_str*) node->nod_arg[e_fln_name];
		if (string != 0) {
			trace_line("%s\"\n", string->str_data);
		}
		else {
			trace_line("%s\"\n", "*");
		}
		return;

	case nod_var_name:
		trace_line("%svariable name: \"", buffer);
		string = (dsql_str*) node->nod_arg[e_vrn_name];
		trace_line("%s\"\n", string->str_data);
		return;

	case nod_mod_udf:
		verb = "mod_udf";
		break;

	case nod_returning:
		verb = "returning";
		break;

	case nod_tra_misc:
		verb = "tra_misc";
		break;

	case nod_lock_timeout:
		verb = "lock_timeout"; // maybe show the timeout value?
		break;

	case nod_src_info:
		{
			const int line = (int) (IPTR) (*ptr++);
			const int col = (int) (IPTR) (*ptr++);
			sprintf(s, "src_info: line %d, col %d", line, col);
		}
		verb = s;
		break;

	case nod_with:
		verb = "with";
		break;

	case nod_update_or_insert:
		verb = "update_or_insert";
		break;

	case nod_merge:
		verb = "merge";
		break;

	case nod_merge_when:
		verb = "merge_when";
		break;

	case nod_merge_update:
		verb = "merge_update";
		break;

	case nod_merge_delete:
		verb = "merge_delete";
		break;

	case nod_merge_insert:
		verb = "merge_insert";
		break;

	case nod_mod_role:
		verb = "mod_role";
		break;

	case nod_add_user:
		verb = "add_user";
		break;

	case nod_mod_user:
		verb = "mod_user";
		break;

	case nod_del_user:
		verb = "del_user";
		break;

	case nod_class_exprnode:
	case nod_class_stmtnode:
		reinterpret_cast<Node*>(node->nod_arg[0])->print(verb, subNodes);
		ptr = subNodes.begin();
		end = subNodes.end();
		break;

	case nod_mod_field_null_flag:
		verb = "mod_field_null_flag";
		break;

	default:
		sprintf(s, "unknown type %d", node->nod_type);
		verb = s;
	}

	if (node->nod_desc.dsc_dtype)
	{
		trace_line("%s%s (%d,%d,%p)\n",
				buffer, verb.c_str(),
				node->nod_desc.dsc_dtype, node->nod_desc.dsc_length, node->nod_desc.dsc_address);
	}
	else
		trace_line("%s%s\n", buffer, verb.c_str());

	++column;

	while (ptr < end)
		DSQL_pretty(*ptr++, column);

	return;
}
#endif