greenplumn CXformDifferenceAll2LeftAntiSemiJoin 代码
文件路径：/src/backend/gporca/libgpopt/src/xforms/CXformDifferenceAll2LeftAntiSemiJoin.cpp
/---------------------------------------------------------------------------
/ Greenplum Database
/ Copyright (C) 2013 EMC Corp.
/
/ @filename:
/ CXformDifferenceAll2LeftAntiSemiJoin.cpp
/
/ @doc:
/ Implementation of the transformation a logical difference all into LASJ
/---------------------------------------------------------------------------
#include "gpopt/xforms/CXformDifferenceAll2LeftAntiSemiJoin.h"
#include "gpos/base.h"
#include "gpopt/exception.h"
#include "gpopt/operators/CLogicalDifferenceAll.h"
#include "gpopt/operators/CLogicalLeftAntiSemiJoin.h"
#include "gpopt/operators/CPatternMultiLeaf.h"
#include "gpopt/xforms/CXformIntersectAll2LeftSemiJoin.h"
#include "gpopt/xforms/CXformUtils.h"
using namespace gpopt;
/---------------------------------------------------------------------------
/ @function:
/ CXformDifferenceAll2LeftAntiSemiJoin::CXformDifferenceAll2LeftAntiSemiJoin
/
/ @doc:
/ Ctor
/
/---------------------------------------------------------------------------
CXformDifferenceAll2LeftAntiSemiJoin::CXformDifferenceAll2LeftAntiSemiJoin(
CMemoryPool *mp)
: / pattern
CXformExploration(GPOS_NEW(mp) CExpression(
mp, GPOS_NEW(mp) CLogicalDifferenceAll(mp),
GPOS_NEW(mp) CExpression(mp, GPOS_NEW(mp) CPatternMultiLeaf(mp))))
{
}
/---------------------------------------------------------------------------
/ @function:
/ CXformDifferenceAll2LeftAntiSemiJoin::Transform
/
/ @doc:
/ Actual transformation
/
/---------------------------------------------------------------------------
void
CXformDifferenceAll2LeftAntiSemiJoin::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();
/ TODO: , Jan 8th 2013, we currently only handle difference all
/ operators with two children
GPOS_ASSERT(2 == pexpr->Arity());
/ extract components
CExpression *pexprLeftChild = (*pexpr)[0];
CExpression *pexprRightChild = (*pexpr)[1];
CLogicalDifferenceAll *popDifferenceAll =
CLogicalDifferenceAll::PopConvert(pexpr->Pop());
CColRef2dArray *pdrgpdrgpcrInput = popDifferenceAll->PdrgpdrgpcrInput();
CExpression *pexprLeftWindow = CXformUtils::PexprWindowWithRowNumber(
mp, pexprLeftChild, (*pdrgpdrgpcrInput)[0]);
CExpression *pexprRightWindow = CXformUtils::PexprWindowWithRowNumber(
mp, pexprRightChild, (*pdrgpdrgpcrInput)[1]);
CColRef2dArray *pdrgpdrgpcrInputNew = GPOS_NEW(mp) CColRef2dArray(mp);
CColRefArray *pdrgpcrLeftNew =
CUtils::PdrgpcrExactCopy(mp, (*pdrgpdrgpcrInput)[0]);
pdrgpcrLeftNew->Append(CXformUtils::PcrProjectElement(
pexprLeftWindow, 0 /* row_number window function*/));
CColRefArray *pdrgpcrRightNew =
CUtils::PdrgpcrExactCopy(mp, (*pdrgpdrgpcrInput)[1]);
pdrgpcrRightNew->Append(CXformUtils::PcrProjectElement(
pexprRightWindow, 0 /* row_number window function*/));
pdrgpdrgpcrInputNew->Append(pdrgpcrLeftNew);
pdrgpdrgpcrInputNew->Append(pdrgpcrRightNew);
/ generate the scalar condition for the left anti-semi join
CExpression *pexprScCond =
CUtils::PexprConjINDFCond(mp, pdrgpdrgpcrInputNew);
/ assemble the new left anti-semi join logical operator
CExpression *pexprLASJ = GPOS_NEW(mp)
CExpression(mp, GPOS_NEW(mp) CLogicalLeftAntiSemiJoin(mp),
pexprLeftWindow, pexprRightWindow, pexprScCond);
/ clean up
pdrgpdrgpcrInputNew->Release();
/ add alternative to results
pxfres->Add(pexprLASJ);
}
/ EOF
相关信息
相关文章
greenplumn CJoinOrderGreedy 源码
greenplumn CJoinOrderMinCard 源码
greenplumn CSubqueryHandler 源码