greenplumn CXformDelete2DML 代码
文件路径：/src/backend/gporca/libgpopt/src/xforms/CXformDelete2DML.cpp
/---------------------------------------------------------------------------
/ Greenplum Database
/ Copyright (C) 2012 EMC Corp.
/
/ @filename:
/ CXformDelete2DML.cpp
/
/ @doc:
/ Implementation of transform
/---------------------------------------------------------------------------
#include "gpopt/xforms/CXformDelete2DML.h"
#include "gpos/base.h"
#include "gpopt/metadata/CTableDescriptor.h"
#include "gpopt/operators/CLogicalDelete.h"
#include "gpopt/operators/CPatternLeaf.h"
#include "gpopt/xforms/CXformUtils.h"
using namespace gpopt;
/---------------------------------------------------------------------------
/ @function:
/ CXformDelete2DML::CXformDelete2DML
/
/ @doc:
/ Ctor
/
/---------------------------------------------------------------------------
CXformDelete2DML::CXformDelete2DML(CMemoryPool *mp)
: CXformExploration(
/ pattern
GPOS_NEW(mp) CExpression(
mp, GPOS_NEW(mp) CLogicalDelete(mp),
GPOS_NEW(mp) CExpression(mp, GPOS_NEW(mp) CPatternLeaf(mp))))
{
}
/---------------------------------------------------------------------------
/ @function:
/ CXformDelete2DML::Exfp
/
/ @doc:
/ Compute promise of xform
/
/---------------------------------------------------------------------------
CXform::EXformPromise
CXformDelete2DML::Exfp(CExpressionHandle & / exprhdl
) const
{
return CXform::ExfpHigh;
}
/---------------------------------------------------------------------------
/ @function:
/ CXformDelete2DML::Transform
/
/ @doc:
/ Actual transformation
/
/---------------------------------------------------------------------------
void
CXformDelete2DML::Transform(CXformContext *pxfctxt, CXformResult *pxfres,
CExpression *pexpr) const
{
GPOS_ASSERT(nullptr != pxfctxt);
GPOS_ASSERT(FPromising(pxfctxt->Pmp(), this, pexpr));
GPOS_ASSERT(FCheckPattern(pexpr));
CLogicalDelete *popDelete = CLogicalDelete::PopConvert(pexpr->Pop());
CMemoryPool *mp = pxfctxt->Pmp();
/ extract components for alternative
CTableDescriptor *ptabdesc = popDelete->Ptabdesc();
ptabdesc->AddRef();
CColRefArray *colref_array = popDelete->Pdrgpcr();
colref_array->AddRef();
CColRef *pcrCtid = popDelete->PcrCtid();
CColRef *pcrSegmentId = popDelete->PcrSegmentId();
/ child of delete operator
CExpression *pexprChild = (*pexpr)[0];
pexprChild->AddRef();
/ create logical DML
CExpression *pexprAlt = CXformUtils::PexprLogicalDMLOverProject(
mp, pexprChild, CLogicalDML::EdmlDelete, ptabdesc, colref_array,
pcrCtid, pcrSegmentId);
/ add alternative to transformation result
pxfres->Add(pexprAlt);
}
/ EOF
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