greenplumn CXformMaxOneRow2Assert 代码
文件路径：/src/backend/gporca/libgpopt/src/xforms/CXformMaxOneRow2Assert.cpp
/---------------------------------------------------------------------------
/ Greenplum Database
/ Copyright (C) 2014 VMware, Inc. or its affiliates.
/
/ @filename:
/ CXformMaxOneRow2Assert.cpp
/
/ @doc:
/ Implementation of transform
/---------------------------------------------------------------------------
#include "gpopt/xforms/CXformMaxOneRow2Assert.h"
#include "gpos/base.h"
#include "gpopt/operators/CLogicalMaxOneRow.h"
#include "gpopt/operators/CPatternLeaf.h"
#include "gpopt/xforms/CXformUtils.h"
using namespace gpopt;
/---------------------------------------------------------------------------
/ @function:
/ CXformMaxOneRow2Assert::CXformMaxOneRow2Assert
/
/ @doc:
/ Ctor
/
/---------------------------------------------------------------------------
CXformMaxOneRow2Assert::CXformMaxOneRow2Assert(CMemoryPool *mp)
: CXformExploration(
/ pattern
GPOS_NEW(mp) CExpression(
mp, GPOS_NEW(mp) CLogicalMaxOneRow(mp),
GPOS_NEW(mp) CExpression(mp, GPOS_NEW(mp) CPatternLeaf(mp))))
{
}
/---------------------------------------------------------------------------
/ @function:
/ CXformMaxOneRow2Assert::Exfp
/
/ @doc:
/ Compute promise of xform
/
/---------------------------------------------------------------------------
CXform::EXformPromise
CXformMaxOneRow2Assert::Exfp(CExpressionHandle & / exprhdl
) const
{
return CXform::ExfpHigh;
}
/---------------------------------------------------------------------------
/ @function:
/ CXformMaxOneRow2Assert::Transform
/
/ @doc:
/ Actual transformation
/
/---------------------------------------------------------------------------
void
CXformMaxOneRow2Assert::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();
/ create Logical Assert that checks if more than one rows are generated by child
CExpression *pexprAlt = CXformUtils::PexprAssertOneRow(mp, (*pexpr)[0]);
/ add alternative to transformation result
pxfres->Add(pexprAlt);
}
/ EOF
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