greenplumn CXformGet2TableScan 代码
文件路径：/src/backend/gporca/libgpopt/src/xforms/CXformGet2TableScan.cpp
/---------------------------------------------------------------------------
/ Greenplum Database
/ Copyright (C) 2009 Greenplum, Inc.
/
/ @filename:
/ CXformGet2TableScan.cpp
/
/ @doc:
/ Implementation of transform
/---------------------------------------------------------------------------
#include "gpopt/xforms/CXformGet2TableScan.h"
#include "gpos/base.h"
#include "gpopt/metadata/CTableDescriptor.h"
#include "gpopt/operators/CExpressionHandle.h"
#include "gpopt/operators/CLogicalGet.h"
#include "gpopt/operators/CPhysicalTableScan.h"
using namespace gpopt;
/---------------------------------------------------------------------------
/ @function:
/ CXformGet2TableScan::CXformGet2TableScan
/
/ @doc:
/ Ctor
/
/---------------------------------------------------------------------------
CXformGet2TableScan::CXformGet2TableScan(CMemoryPool *mp)
: CXformImplementation(
/ pattern
GPOS_NEW(mp) CExpression(mp, GPOS_NEW(mp) CLogicalGet(mp)))
{
}
/---------------------------------------------------------------------------
/ @function:
/ CXformGet2TableScan::Exfp
/
/ @doc:
/ Compute promise of xform
/
/---------------------------------------------------------------------------
CXform::EXformPromise
CXformGet2TableScan::Exfp(CExpressionHandle &exprhdl) const
{
CLogicalGet *popGet = CLogicalGet::PopConvert(exprhdl.Pop());
CTableDescriptor *ptabdesc = popGet->Ptabdesc();
if (ptabdesc->IsPartitioned())
{
return CXform::ExfpNone;
}
return CXform::ExfpHigh;
}
/---------------------------------------------------------------------------
/ @function:
/ CXformGet2TableScan::Transform
/
/ @doc:
/ Actual transformation
/
/---------------------------------------------------------------------------
void
CXformGet2TableScan::Transform(CXformContext *pxfctxt, CXformResult *pxfres,
CExpression *pexpr) const
{
GPOS_ASSERT(nullptr != pxfctxt);
GPOS_ASSERT(FPromising(pxfctxt->Pmp(), this, pexpr));
GPOS_ASSERT(FCheckPattern(pexpr));
CLogicalGet *popGet = CLogicalGet::PopConvert(pexpr->Pop());
CMemoryPool *mp = pxfctxt->Pmp();
/ create/extract components for alternative
CName *pname = GPOS_NEW(mp) CName(mp, popGet->Name());
CTableDescriptor *ptabdesc = popGet->Ptabdesc();
ptabdesc->AddRef();
CColRefArray *pdrgpcrOutput = popGet->PdrgpcrOutput();
GPOS_ASSERT(nullptr != pdrgpcrOutput);
pdrgpcrOutput->AddRef();
/ create alternative expression
CExpression *pexprAlt = GPOS_NEW(mp) CExpression(
mp,
GPOS_NEW(mp) CPhysicalTableScan(mp, pname, ptabdesc, pdrgpcrOutput));
/ add alternative to transformation result
pxfres->Add(pexprAlt);
}
/ EOF
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