greenplumn CLogicalLeftOuterCorrelatedApply 代码
文件路径：/src/backend/gporca/libgpopt/src/operators/CLogicalLeftOuterCorrelatedApply.cpp
/---------------------------------------------------------------------------
/ Greenplum Database
/ Copyright (C) 2012 EMC Corp.
/
/ @filename:
/ CLogicalLeftOuterCorrelatedApply.cpp
/
/ @doc:
/ Implementation of left outer correlated apply operator
/---------------------------------------------------------------------------
#include "gpopt/operators/CLogicalLeftOuterCorrelatedApply.h"
#include "gpos/base.h"
using namespace gpopt;
/---------------------------------------------------------------------------
/ @function:
/ CLogicalLeftOuterCorrelatedApply::CLogicalLeftOuterCorrelatedApply
/
/ @doc:
/ Ctor - for patterns
/
/---------------------------------------------------------------------------
CLogicalLeftOuterCorrelatedApply::CLogicalLeftOuterCorrelatedApply(
CMemoryPool *mp)
: CLogicalLeftOuterApply(mp)
{
}
/---------------------------------------------------------------------------
/ @function:
/ CLogicalLeftOuterCorrelatedApply::CLogicalLeftOuterCorrelatedApply
/
/ @doc:
/ Ctor
/
/---------------------------------------------------------------------------
CLogicalLeftOuterCorrelatedApply::CLogicalLeftOuterCorrelatedApply(
CMemoryPool *mp, CColRefArray *pdrgpcrInner, EOperatorId eopidOriginSubq)
: CLogicalLeftOuterApply(mp, pdrgpcrInner, eopidOriginSubq),
/ In the case of subquery all, we cannot push down the predicate.
/ Example query:
/
/ SELECT (SELECT 1) = ALL (SELECT generate_series(1, 2));
/
/ Physical plan:
/ ```
/ +--CPhysicalComputeScalar
/ |--CPhysicalCorrelatedLeftOuterNLJoin
/ | |--CPhysicalConstTableGet Columns: ["" (0)]
/ | |--CPhysicalComputeScalar
/ | | |--CPhysicalCorrelatedLeftOuterNLJoin
/ | | | |--CPhysicalComputeScalar
/ | | | | |--CPhysicalConstTableGet Columns: ["" (1)] Values: [(1)]
/ | | | | +--CScalarProjectList
/ | | | | +--CScalarProjectElement "generate_series" (2)
/ | | | | +--CScalarFunc (generate_series)
/ | | | | |--CScalarConst (1)
/ | | | | +--CScalarConst (2)
/ | | | |--CPhysicalComputeScalar
/ | | | | |--CPhysicalConstTableGet Columns: ["" (3)] Values: [(1)]
/ | | | | +--CScalarProjectList
/ | | | | +--CScalarProjectElement "?column?" (4)
/ | | | | +--CScalarConst (1)
/ | | | +--CScalarConst (1)
/ | | +--CScalarProjectList
/ | | +--CScalarProjectElement "ColRef_0006" (6)
/ | | +--CScalarConst (1)
/ | +--CScalarCmp (=)
/ | |--CScalarIdent "?column?" (4)
/ | +--CScalarIdent "generate_series" (2)
/ +--CScalarProjectList
/ +--CScalarProjectElement "?column?" (5)
/ +--CScalarIdent "ColRef_0006" (6)
/ ```
/
/ If we push down CScalarCmp as a filter then we would incorrectly
/ discard the tuple 2 output from generate_series. Instead we want to
/ preserve it for a NULL match in the LOJ so that we correctly evaulate
/ subplan ALL_SUBLINK.
m_allow_predicate_pushdown(COperator::EopScalarSubqueryAll !=
eopidOriginSubq)
{
}
/---------------------------------------------------------------------------
/ @function:
/ CLogicalLeftOuterCorrelatedApply::PxfsCandidates
/
/ @doc:
/ Get candidate xforms
/
/---------------------------------------------------------------------------
CXformSet *
CLogicalLeftOuterCorrelatedApply::PxfsCandidates(CMemoryPool *mp) const
{
CXformSet *xform_set = GPOS_NEW(mp) CXformSet(mp);
(void) xform_set->ExchangeSet(CXform::ExfImplementLeftOuterCorrelatedApply);
return xform_set;
}
/---------------------------------------------------------------------------
/ @function:
/ CLogicalLeftOuterCorrelatedApply::Matches
/
/ @doc:
/ Match function
/
/---------------------------------------------------------------------------
BOOL
CLogicalLeftOuterCorrelatedApply::Matches(COperator *pop) const
{
if (pop->Eopid() == Eopid())
{
return m_pdrgpcrInner->Equals(
CLogicalLeftOuterCorrelatedApply::PopConvert(pop)->PdrgPcrInner());
}
return false;
}
/---------------------------------------------------------------------------
/ @function:
/ CLogicalLeftOuterCorrelatedApply::PopCopyWithRemappedColumns
/
/ @doc:
/ Return a copy of the operator with remapped columns
/
/---------------------------------------------------------------------------
COperator *
CLogicalLeftOuterCorrelatedApply::PopCopyWithRemappedColumns(
CMemoryPool *mp, UlongToColRefMap *colref_mapping, BOOL must_exist)
{
CColRefArray *pdrgpcrInner =
CUtils::PdrgpcrRemap(mp, m_pdrgpcrInner, colref_mapping, must_exist);
return GPOS_NEW(mp)
CLogicalLeftOuterCorrelatedApply(mp, pdrgpcrInner, m_eopidOriginSubq);
}
/ EOF
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