greenplumn CXformGbAgg2ScalarAgg 源码

greenplumn CXformGbAgg2ScalarAgg 代码

文件路径：/src/backend/gporca/libgpopt/src/xforms/CXformGbAgg2ScalarAgg.cpp

//---------------------------------------------------------------------------
//	Greenplum Database
//	Copyright (C) 2011 EMC Corp.
//
//	@filename:
//		CXformGbAgg2ScalarAgg.cpp
//
//	@doc:
//		Implementation of transform
//---------------------------------------------------------------------------

#include "gpopt/xforms/CXformGbAgg2ScalarAgg.h"

#include "gpos/base.h"

#include "gpopt/operators/CLogicalGbAgg.h"
#include "gpopt/operators/CPatternLeaf.h"
#include "gpopt/operators/CPhysicalScalarAgg.h"
#include "gpopt/xforms/CXformGbAgg2HashAgg.h"
#include "gpopt/xforms/CXformUtils.h"

using namespace gpopt;


//---------------------------------------------------------------------------
//	@function:
//		CXformGbAgg2ScalarAgg::CXformGbAgg2ScalarAgg
//
//	@doc:
//		Ctor
//
//---------------------------------------------------------------------------
CXformGbAgg2ScalarAgg::CXformGbAgg2ScalarAgg(CMemoryPool *mp)
	: CXformImplementation(
		  // pattern
		  GPOS_NEW(mp) CExpression(
			  mp, GPOS_NEW(mp) CLogicalGbAgg(mp),
			  GPOS_NEW(mp) CExpression(mp, GPOS_NEW(mp) CPatternLeaf(mp)),
			  GPOS_NEW(mp) CExpression(mp, GPOS_NEW(mp) CPatternLeaf(mp))))
{
}


//---------------------------------------------------------------------------
//	@function:
//		CXformGbAgg2ScalarAgg::Exfp
//
//	@doc:
//		Compute xform promise for a given expression handle;
//		grouping columns must be empty
//
//---------------------------------------------------------------------------
CXform::EXformPromise
CXformGbAgg2ScalarAgg::Exfp(CExpressionHandle &exprhdl) const
{
	if (0 < CLogicalGbAgg::PopConvert(exprhdl.Pop())->Pdrgpcr()->Size() ||
		exprhdl.DeriveHasSubquery(1))
	{
		// GbAgg has grouping columns, or agg functions use subquery arguments
		return CXform::ExfpNone;
	}

	return CXform::ExfpHigh;
}


//---------------------------------------------------------------------------
//	@function:
//		CXformGbAgg2ScalarAgg::Transform
//
//	@doc:
//		Actual transformation
//
//---------------------------------------------------------------------------
void
CXformGbAgg2ScalarAgg::Transform(CXformContext *pxfctxt, CXformResult *pxfres,
								 CExpression *pexpr) const
{
	GPOS_ASSERT(nullptr != pxfctxt);
	GPOS_ASSERT(FPromising(pxfctxt->Pmp(), this, pexpr));
	GPOS_ASSERT(FCheckPattern(pexpr));

	CLogicalGbAgg *popAgg = CLogicalGbAgg::PopConvert(pexpr->Pop());
	CMemoryPool *mp = pxfctxt->Pmp();
	CColRefArray *colref_array = popAgg->Pdrgpcr();
	colref_array->AddRef();

	// extract components
	CExpression *pexprRel = (*pexpr)[0];
	CExpression *pexprScalar = (*pexpr)[1];

	// addref children
	pexprRel->AddRef();
	pexprScalar->AddRef();

	CColRefArray *pdrgpcrArgDQA = popAgg->PdrgpcrArgDQA();
	if (pdrgpcrArgDQA != nullptr && 0 != pdrgpcrArgDQA->Size())
	{
		pdrgpcrArgDQA->AddRef();
	}

	// create alternative expression
	CExpression *pexprAlt = GPOS_NEW(mp) CExpression(
		mp,
		GPOS_NEW(mp) CPhysicalScalarAgg(
			mp, colref_array, popAgg->PdrgpcrMinimal(), popAgg->Egbaggtype(),
			popAgg->FGeneratesDuplicates(), pdrgpcrArgDQA,
			CXformUtils::FMultiStageAgg(pexpr),
			CXformUtils::FAggGenBySplitDQAXform(pexpr), popAgg->AggStage(),
			!CXformUtils::FLocalAggCreatedByEagerAggXform(pexpr)),
		pexprRel, pexprScalar);

	// add alternative to transformation result
	pxfres->Add(pexprAlt);
}


// EOF

相关信息

greenplumn 源码目录

相关文章

greenplumn CDecorrelator 源码

greenplumn CJoinOrder 源码

greenplumn CJoinOrderDP 源码

greenplumn CJoinOrderDPv2 源码

greenplumn CJoinOrderGreedy 源码

greenplumn CJoinOrderMinCard 源码

greenplumn CSubqueryHandler 源码

greenplumn CXform 源码

greenplumn CXformCTEAnchor2Sequence 源码

greenplumn CXformCTEAnchor2TrivialSelect 源码