greenplumn CXformPushGbBelowJoin 代码
文件路径：/src/backend/gporca/libgpopt/src/xforms/CXformPushGbBelowJoin.cpp
/---------------------------------------------------------------------------
/ Greenplum Database
/ Copyright (C) 2012 EMC Corp.
/
/ @filename:
/ CXformPushGbBelowJoin.cpp
/
/ @doc:
/ Implementation of pushing group by below join transform
/---------------------------------------------------------------------------
#include "gpopt/xforms/CXformPushGbBelowJoin.h"
#include "gpos/base.h"
#include "gpopt/operators/CLogicalGbAgg.h"
#include "gpopt/operators/CLogicalInnerJoin.h"
#include "gpopt/operators/CPatternLeaf.h"
#include "gpopt/xforms/CXformUtils.h"
using namespace gpopt;
/---------------------------------------------------------------------------
/ @function:
/ CXformPushGbBelowJoin::CXformPushGbBelowJoin
/
/ @doc:
/ Ctor
/
/---------------------------------------------------------------------------
CXformPushGbBelowJoin::CXformPushGbBelowJoin(CMemoryPool *mp)
: / pattern
CXformExploration(GPOS_NEW(mp) CExpression(
mp, GPOS_NEW(mp) CLogicalGbAgg(mp),
GPOS_NEW(mp) CExpression(
mp, GPOS_NEW(mp) CLogicalInnerJoin(mp),
GPOS_NEW(mp) CExpression(
mp, GPOS_NEW(mp) CPatternLeaf(mp)), / join outer child
GPOS_NEW(mp) CExpression(
mp, GPOS_NEW(mp) CPatternLeaf(mp)), / join inner child
GPOS_NEW(mp) CExpression(
mp, GPOS_NEW(mp) CPatternTree(mp)) / join predicate
),
GPOS_NEW(mp) CExpression(
mp, GPOS_NEW(mp) CPatternTree(mp)) / scalar project list
))
{
}
/---------------------------------------------------------------------------
/ @function:
/ CXformPushGbBelowJoin::CXformPushGbBelowJoin
/
/ @doc:
/ Ctor
/
/---------------------------------------------------------------------------
CXformPushGbBelowJoin::CXformPushGbBelowJoin(CExpression *pexprPattern)
: CXformExploration(pexprPattern)
{
}
/---------------------------------------------------------------------------
/ @function:
/ CXformPushGbBelowJoin::Exfp
/
/ @doc:
/ Compute xform promise for a given expression handle;
/ we only push down global aggregates
/
/---------------------------------------------------------------------------
CXform::EXformPromise
CXformPushGbBelowJoin::Exfp(CExpressionHandle &exprhdl) const
{
CLogicalGbAgg *popGbAgg = CLogicalGbAgg::PopConvert(exprhdl.Pop());
if (!popGbAgg->FGlobal())
{
return CXform::ExfpNone;
}
return CXform::ExfpHigh;
}
/---------------------------------------------------------------------------
/ @function:
/ CXformPushGbBelowJoin::Transform
/
/ @doc:
/ Actual transformation
/
/---------------------------------------------------------------------------
void
CXformPushGbBelowJoin::Transform(CXformContext *pxfctxt, CXformResult *pxfres,
CExpression *pexpr) const
{
GPOS_ASSERT(nullptr != pxfctxt);
GPOS_ASSERT(FPromising(pxfctxt->Pmp(), this, pexpr));
GPOS_ASSERT(FCheckPattern(pexpr));
CMemoryPool *mp = pxfctxt->Pmp();
CExpression *pexprResult = CXformUtils::PexprPushGbBelowJoin(mp, pexpr);
if (nullptr != pexprResult)
{
/ add alternative to results
pxfres->Add(pexprResult);
}
}
/ EOF
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