greenplumn CXformImplementUnionAll 代码
文件路径：/src/backend/gporca/libgpopt/src/xforms/CXformImplementUnionAll.cpp
/---------------------------------------------------------------------------
/ Greenplum Database
/ Copyright (C) 2012 EMC Corp.
/
/ @filename:
/ CXformImplementUnionAll.cpp
/
/ @doc:
/ Implementation of union all operator
/---------------------------------------------------------------------------
#include "gpopt/xforms/CXformImplementUnionAll.h"
#include "gpos/base.h"
#include "gpopt/exception.h"
#include "gpopt/operators/CLogicalUnionAll.h"
#include "gpopt/operators/CPatternMultiLeaf.h"
#include "gpopt/operators/CPhysicalUnionAll.h"
#include "gpopt/operators/CPhysicalUnionAllFactory.h"
#include "gpopt/xforms/CXformUtils.h"
using namespace gpopt;
/---------------------------------------------------------------------------
/ @function:
/ CXformImplementUnionAll::CXformImplementUnionAll
/
/ @doc:
/ Ctor
/
/---------------------------------------------------------------------------
CXformImplementUnionAll::CXformImplementUnionAll(CMemoryPool *mp)
: / pattern
CXformImplementation(GPOS_NEW(mp) CExpression(
mp, GPOS_NEW(mp) CLogicalUnionAll(mp),
GPOS_NEW(mp) CExpression(mp, GPOS_NEW(mp) CPatternMultiLeaf(mp))))
{
}
/---------------------------------------------------------------------------
/ @function:
/ CXformImplementUnionAll::Transform
/
/ @doc:
/ Actual transformation
/
/---------------------------------------------------------------------------
void
CXformImplementUnionAll::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();
/ extract components
CLogicalUnionAll *popUnionAll = CLogicalUnionAll::PopConvert(pexpr->Pop());
CPhysicalUnionAllFactory factory(popUnionAll);
CExpressionArray *pdrgpexpr = GPOS_NEW(mp) CExpressionArray(mp);
const ULONG arity = pexpr->Arity();
for (ULONG ul = 0; ul < arity; ul++)
{
CExpression *pexprChild = (*pexpr)[ul];
pexprChild->AddRef();
pdrgpexpr->Append(pexprChild);
}
CPhysicalUnionAll *popPhysicalSerialUnionAll =
factory.PopPhysicalUnionAll(mp, false);
/ assemble serial union physical operator
CExpression *pexprSerialUnionAll =
GPOS_NEW(mp) CExpression(mp, popPhysicalSerialUnionAll, pdrgpexpr);
/ add serial union alternative to results
pxfres->Add(pexprSerialUnionAll);
/ parallel union alternative to the result if the GUC is on
BOOL fParallel = GPOS_FTRACE(EopttraceEnableParallelAppend);
if (fParallel)
{
CPhysicalUnionAll *popPhysicalParallelUnionAll =
factory.PopPhysicalUnionAll(mp, true);
pdrgpexpr->AddRef();
/ assemble physical parallel operator
CExpression *pexprParallelUnionAll = GPOS_NEW(mp)
CExpression(mp, popPhysicalParallelUnionAll, pdrgpexpr);
/ add parallel union alternative to results
pxfres->Add(pexprParallelUnionAll);
}
}
/ EOF
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