Added the ability to change deterministic option (#7758)

* Added the ability to change deterministic option
Added the ability to change deterministic opt without specifiying the entire body of the function.
Extended "ALTER FUNCTION" syntax:
ALTER FUNCTION <name> DETERMINISTIC;
ALTER FUNCTION <name> NOT DETERMINISTIC;

* added const qualifier to flag, removed nested if/else

* added doc

---------

Co-authored-by: Alexander Zhdanov <alexander.zhdanov@red-soft.ru>

doc/sql.extensions/README.ddl.txt

@@ -603,3 +603,8 @@ ALTER TABLE <name> ... [ {ENABLE | DISABLE} PUBLICATION ]
 
 Defines whether replication is enabled for the specified table.
 If not specified in the CREATE TABLE statement, the database-level default behaviour is applied.
+
+24) Added the ability to change deterministic option without specifying the entire body of the function.
+(Alexander Zhdanov)
+
+ALTER FUNCTION <name> {DETERMINISTIC | NOT DETERMINISTIC}

src/dsql/DdlNodes.epp

@@ -1726,10 +1726,19 @@ void CreateAlterFunctionNode::execute(thread_db* tdbb, DsqlCompilerScratch* dsql
 	AutoSavePoint savePoint(tdbb, transaction);
 	bool altered = false;
 
+	const bool alterIndividualParameters = !(body || external);
+
 	// first pass
 	if (alter)
 	{
-		if (executeAlter(tdbb, dsqlScratch, transaction, false, true))
+		if (alterIndividualParameters)
+		{
+			if (executeAlterIndividualParameters(tdbb, dsqlScratch, transaction, false, true))
+				altered = true;
+			else
+				status_exception::raise(Arg::Gds(isc_dyn_func_not_found) << Arg::Str(name));
+		}
+		else if (executeAlter(tdbb, dsqlScratch, transaction, false, true))
 		{
 			altered = true;
 		}
@@ -1746,7 +1755,12 @@ void CreateAlterFunctionNode::execute(thread_db* tdbb, DsqlCompilerScratch* dsql
 
 	compile(tdbb, dsqlScratch);
 
-	executeAlter(tdbb, dsqlScratch, transaction, true, false);	// second pass
+	// second pass
+	if (alterIndividualParameters)
+		executeAlterIndividualParameters(tdbb, dsqlScratch, transaction, true, false);
+	else
+		executeAlter(tdbb, dsqlScratch, transaction, true, false);
+
 
 	if (package.isEmpty())
 	{
@@ -2062,6 +2076,43 @@ bool CreateAlterFunctionNode::executeAlter(thread_db* tdbb, DsqlCompilerScratch*
 	return modified;
 }
 
+bool CreateAlterFunctionNode::executeAlterIndividualParameters(thread_db* tdbb, DsqlCompilerScratch* dsqlScratch, jrd_tra* transaction, bool secondPass, bool runTriggers)
+{
+	Attachment* const attachment = transaction->getAttachment();
+
+	bool modifed = false;
+
+	AutoCacheRequest requestHandle(tdbb, drq_m_prm_funcs2, DYN_REQUESTS);
+
+	FOR (REQUEST_HANDLE requestHandle TRANSACTION_HANDLE transaction)
+		FUN IN RDB$FUNCTIONS
+		WITH FUN.RDB$FUNCTION_NAME EQ name.c_str() AND
+			 FUN.RDB$PACKAGE_NAME EQUIV NULLIF(package.c_str(), '')
+	{
+		if (FUN.RDB$SYSTEM_FLAG)
+		{
+			status_exception::raise(
+				Arg::Gds(isc_dyn_cannot_mod_sysfunc) << MetaName(FUN.RDB$FUNCTION_NAME));
+		}
+
+		if (!secondPass && runTriggers && package.isEmpty())
+		{
+			executeDdlTrigger(tdbb, dsqlScratch, transaction, DTW_BEFORE,
+				DDL_TRIGGER_ALTER_FUNCTION, name, NULL);
+		}
+
+		MODIFY FUN
+			FUN.RDB$DETERMINISTIC_FLAG.NULL = FALSE;
+			FUN.RDB$DETERMINISTIC_FLAG = deterministic ? TRUE : FALSE;
+
+			modifed = true;
+		END_MODIFY
+	}
+	END_FOR
+
+	return modifed;
+}
+
 void CreateAlterFunctionNode::storeArgument(thread_db* tdbb, DsqlCompilerScratch* dsqlScratch,
 	jrd_tra* transaction, unsigned pos, bool returnArg, ParameterClause* parameter,
 	const CollectedParameter* collectedParameter)

src/dsql/DdlNodes.h

@@ -455,6 +455,8 @@ private:
 	void executeCreate(thread_db* tdbb, DsqlCompilerScratch* dsqlScratch, jrd_tra* transaction);
 	bool executeAlter(thread_db* tdbb, DsqlCompilerScratch* dsqlScratch, jrd_tra* transaction,
 		bool secondPass, bool runTriggers);
+	bool executeAlterIndividualParameters(thread_db* tdbb, DsqlCompilerScratch* dsqlScratch, jrd_tra* transaction,
+		bool secondPass, bool runTriggers);
 
 	void storeArgument(thread_db* tdbb, DsqlCompilerScratch* dsqlScratch, jrd_tra* transaction,
 		unsigned pos, bool returnArg, ParameterClause* parameter,

src/dsql/parse.y

@@ -2831,6 +2831,11 @@ function_clause
 	: psql_function_clause
 	| external_function_clause;
 
+%type <createAlterFunctionNode> change_opt_function_clause
+change_opt_function_clause
+	: change_deterministic_opt_function_clause
+	;
+
 %type <createAlterFunctionNode> psql_function_clause
 psql_function_clause
 	: function_clause_start sql_security_clause_opt AS local_declarations_opt full_proc_block
@@ -2859,7 +2864,7 @@ function_clause_start
 	: symbol_UDF_name
 			{ $$ = newNode<CreateAlterFunctionNode>(*$1); }
 		input_parameters(NOTRIAL(&$2->parameters))
-		RETURNS domain_or_non_array_type collate_clause deterministic_opt
+		RETURNS domain_or_non_array_type collate_clause deterministic_clause_opt
 			{
 				$$ = $2;
 				$$->returnType = newNode<ParameterClause>($5, optName($6));
@@ -2867,13 +2872,30 @@ function_clause_start
 			}
 	;
 
-%type <boolVal> deterministic_opt
+%type <createAlterFunctionNode> change_deterministic_opt_function_clause
-deterministic_opt
+change_deterministic_opt_function_clause
-	:					{ $$ = false; }
+	: symbol_UDF_name
-	| NOT DETERMINISTIC	{ $$ = false; }
+			{ $$ = newNode<CreateAlterFunctionNode>(*$1); }
+		deterministic_clause
+			{
+				$$ = $2;
+				$$->deterministic = $3;
+			}
+	;
+
+
+%type <boolVal> deterministic_clause
+deterministic_clause
+	: NOT DETERMINISTIC	{ $$ = false; }
 	| DETERMINISTIC		{ $$ = true; }
 	;
 
+%type <boolVal> deterministic_clause_opt
+deterministic_clause_opt
+	:						{ $$ = false; }
+	| deterministic_clause	{ $$ = $1; }
+	;
+
 %type <externalClause> external_clause
 external_clause
 	: EXTERNAL NAME utf_string ENGINE valid_symbol_name
@@ -2903,6 +2925,12 @@ alter_function_clause
 			$$->alter = true;
 			$$->create = false;
 		}
+	| change_opt_function_clause
+		{
+			$$ = $1;
+			$$->alter = true;
+			$$->create = false;
+		}
 	;
 
 %type <createAlterFunctionNode> replace_function_clause
@@ -3149,7 +3177,7 @@ local_declaration_subfunc_start
 				$$->dsqlBlock = newNode<ExecBlockNode>();
 			}
 		input_parameters(NOTRIAL(&$4->dsqlBlock->parameters))
-		RETURNS domain_or_non_array_type collate_clause deterministic_opt
+		RETURNS domain_or_non_array_type collate_clause deterministic_clause_opt
 			{
 				$$ = $4;
 				$$->dsqlBlock->returns.add(newNode<ParameterClause>($<legacyField>7, optName($8)));

src/jrd/drq.h

@@ -176,6 +176,7 @@ enum drq_type_t
 	drq_s_funcs2,			// store functions (CreateAlterFunctionNode)
 	drq_s_func_args2,		// store function arguments (CreateAlterFunctionNode)
 	drq_m_funcs2,			// modify functions (CreateAlterFunctionNode)
+	drq_m_prm_funcs2,		// modify individual function parameters (CreateAlterFunctionNode)
 	drq_e_func_args2,		// erase function arguments (CreateAlterFunctionNode)
 	drq_s_prcs2,
 	drq_s_prms4,