Frontport the reworked implementation of the full outer join

src/jrd/optimizer/Optimizer.h

@@ -922,7 +922,7 @@ public:
 	RecordSource* generate();
 
 private:
-	RecordSource* process(const JoinType joinType);
+	RecordSource* process(StreamList* outerStreams = nullptr);
 
 	thread_db* const tdbb;
 	Optimizer* const optimizer;

src/jrd/optimizer/OuterJoin.cpp

@@ -94,15 +94,25 @@ OuterJoin::OuterJoin(thread_db* aTdbb, Optimizer* opt,
 
 RecordSource* OuterJoin::generate()
 {
-	const auto outerJoinRsb = process(OUTER_JOIN);
-
 	if (!optimizer->isFullJoin())
-		return outerJoinRsb;
+	{
+		fb_assert(optimizer->isLeftJoin());
+		return process();
+	}
 
-	// A FULL JOIN B is currently implemented similar to (A LEFT JOIN B) UNION ALL (B ANTI-JOIN A).
+	StreamList outerStreams;
+	const auto outerJoinRsb = process(&outerStreams);
+
+	// A FULL JOIN B is currently implemented similar to:
+	//
+	// (A LEFT JOIN B)
+	// UNION ALL
+	// (B LEFT JOIN A WHERE A.* IS NULL)
+	//
+	// See also FullOuterJoin class implementation.
 	//
 	// At this point we already have the first part -- (A LEFT JOIN B) -- ready,
-	// so just swap the sides and make an anti-join.
+	// so just swap the sides and make the second (inverted) join.
 
 	auto& outerStream = joinStreams[0];
 	auto& innerStream = joinStreams[1];
@@ -131,15 +141,15 @@ RecordSource* OuterJoin::generate()
 			iter.reset(CMP_clone_node_opt(tdbb, csb, iter));
 	}
 
-	const auto antiJoinRsb = process(ANTI_JOIN);
+	const auto antiJoinRsb = process();
 
 	// Allocate and return the final join record source
 
-	return FB_NEW_POOL(getPool()) FullOuterJoin(csb, outerJoinRsb, antiJoinRsb);
+	return FB_NEW_POOL(getPool()) FullOuterJoin(csb, outerJoinRsb, antiJoinRsb, outerStreams);
 }
 
 
-RecordSource* OuterJoin::process(const JoinType joinType)
+RecordSource* OuterJoin::process(StreamList* outerStreams)
 {
 	BoolExprNode* boolean = nullptr;
 
@@ -153,8 +163,7 @@ RecordSource* OuterJoin::process(const JoinType joinType)
 	{
 		fb_assert(!outerStream.rsb);
 		outerStream.rsb = optimizer->generateRetrieval(outerStream.number,
-			optimizer->isFullJoin() ? nullptr : sortPtr,
-			true, false, &boolean);
+			optimizer->isFullJoin() ? nullptr : sortPtr, true, false, &boolean);
 	}
 	else
 	{
@@ -173,13 +182,15 @@ RecordSource* OuterJoin::process(const JoinType joinType)
 		boolean = optimizer->composeBoolean();
 	}
 
+	if (outerStreams)
+		outerStream.rsb->findUsedStreams(*outerStreams);
+
 	if (innerStream.number != INVALID_STREAM)
 	{
 		fb_assert(!innerStream.rsb);
 		// AB: the sort clause for the inner stream of an OUTER JOIN
 		//	   should never be used for the index retrieval
-		innerStream.rsb = optimizer->generateRetrieval(innerStream.number, nullptr,
-			false, (joinType == OUTER_JOIN) ? true : false);
+		innerStream.rsb = optimizer->generateRetrieval(innerStream.number, nullptr, false, true);
 	}
 
 	// Generate a parent filter record source for any remaining booleans that
@@ -189,8 +200,7 @@ RecordSource* OuterJoin::process(const JoinType joinType)
 
 	// Allocate and return the join record source
 
-	return FB_NEW_POOL(getPool())
-		NestedLoopJoin(csb, outerStream.rsb, innerRsb, boolean, joinType);
+	return FB_NEW_POOL(getPool()) NestedLoopJoin(csb, outerStream.rsb, innerRsb, boolean);
 };
 
 

src/jrd/recsrc/FullOuterJoin.cpp

@@ -37,10 +37,13 @@ using namespace Jrd;
 // Data access: full outer join
 // ----------------------------
 
-FullOuterJoin::FullOuterJoin(CompilerScratch* csb, RecordSource* arg1, RecordSource* arg2)
+FullOuterJoin::FullOuterJoin(CompilerScratch* csb,
+							 RecordSource* arg1, RecordSource* arg2,
+							 const StreamList& checkStreams)
 	: RecordSource(csb),
 	  m_arg1(arg1),
-	  m_arg2(arg2)
+	  m_arg2(arg2),
+	  m_checkStreams(csb->csb_pool, checkStreams)
 {
 	fb_assert(m_arg1 && m_arg2);
 
@@ -97,7 +100,27 @@ bool FullOuterJoin::internalGetRecord(thread_db* tdbb) const
 		m_arg2->open(tdbb);
 	}
 
-	return m_arg2->getRecord(tdbb);
+	// We should exclude matching records from the right-joined (second) record source,
+	// as they're already returned from the left-joined (first) record source
+
+	while (m_arg2->getRecord(tdbb))
+	{
+		bool matched = false;
+
+		for (const auto stream : m_checkStreams)
+		{
+			if (request->req_rpb[stream].rpb_number.isValid())
+			{
+				matched = true;
+				break;
+			}
+		}
+
+		if (!matched)
+			return true;
+	}
+
+	return false;
 }
 
 bool FullOuterJoin::refetchRecord(thread_db* /*tdbb*/) const

src/jrd/recsrc/NestedLoopJoin.cpp

@@ -53,10 +53,11 @@ NestedLoopJoin::NestedLoopJoin(CompilerScratch* csb, FB_SIZE_T count, RecordSour
 	}
 }
 
-NestedLoopJoin::NestedLoopJoin(CompilerScratch* csb, RecordSource* outer, RecordSource* inner,
-							   BoolExprNode* boolean, JoinType joinType)
+NestedLoopJoin::NestedLoopJoin(CompilerScratch* csb,
+							   RecordSource* outer, RecordSource* inner,
+							   BoolExprNode* boolean)
 	: RecordSource(csb),
-	  m_joinType(joinType),
+	  m_joinType(OUTER_JOIN),
 	  m_args(csb->csb_pool),
 	  m_boolean(boolean)
 {

src/jrd/recsrc/RecordSource.h

@@ -1137,7 +1137,7 @@ namespace Jrd
 	public:
 		NestedLoopJoin(CompilerScratch* csb, FB_SIZE_T count, RecordSource* const* args);
 		NestedLoopJoin(CompilerScratch* csb, RecordSource* outer, RecordSource* inner,
-					   BoolExprNode* boolean, JoinType joinType);
+					   BoolExprNode* boolean);
 
 		void close(thread_db* tdbb) const override;
 
@@ -1168,7 +1168,8 @@ namespace Jrd
 	class FullOuterJoin : public RecordSource
 	{
 	public:
-		FullOuterJoin(CompilerScratch* csb, RecordSource* arg1, RecordSource* arg2);
+		FullOuterJoin(CompilerScratch* csb, RecordSource* arg1, RecordSource* arg2,
+					  const StreamList& checkStreams);
 
 		void close(thread_db* tdbb) const override;
 
@@ -1191,6 +1192,7 @@ namespace Jrd
 	private:
 		NestConst<RecordSource> m_arg1;
 		NestConst<RecordSource> m_arg2;
+		const StreamList m_checkStreams;
 	};
 
 	class HashJoin : public RecordSource