greenplumn CLogicalDifference 代码
文件路径：/src/backend/gporca/libgpopt/src/operators/CLogicalDifference.cpp
/---------------------------------------------------------------------------
/ Greenplum Database
/ Copyright (C) 2012 EMC Corp.
/
/ @filename:
/ CLogicalDifference.cpp
/
/ @doc:
/ Implementation of Difference operator
/---------------------------------------------------------------------------
#include "gpopt/operators/CLogicalDifference.h"
#include "gpos/base.h"
#include "gpopt/base/CKeyCollection.h"
#include "gpopt/base/CUtils.h"
#include "gpopt/operators/CExpressionHandle.h"
#include "gpopt/operators/CLogicalGbAgg.h"
#include "naucrates/statistics/CStatsPredUtils.h"
using namespace gpopt;
/---------------------------------------------------------------------------
/ @function:
/ CLogicalDifference::CLogicalDifference
/
/ @doc:
/ Ctor - for pattern
/
/---------------------------------------------------------------------------
CLogicalDifference::CLogicalDifference(CMemoryPool *mp) : CLogicalSetOp(mp)
{
m_fPattern = true;
}
/---------------------------------------------------------------------------
/ @function:
/ CLogicalDifference::CLogicalDifference
/
/ @doc:
/ Ctor
/
/---------------------------------------------------------------------------
CLogicalDifference::CLogicalDifference(CMemoryPool *mp,
CColRefArray *pdrgpcrOutput,
CColRef2dArray *pdrgpdrgpcrInput)
: CLogicalSetOp(mp, pdrgpcrOutput, pdrgpdrgpcrInput)
{
}
/---------------------------------------------------------------------------
/ @function:
/ CLogicalDifference::~CLogicalDifference
/
/ @doc:
/ Dtor
/
/---------------------------------------------------------------------------
CLogicalDifference::~CLogicalDifference() = default;
/---------------------------------------------------------------------------
/ @function:
/ CLogicalDifference::DeriveMaxCard
/
/ @doc:
/ Derive max card
/
/---------------------------------------------------------------------------
CMaxCard
CLogicalDifference::DeriveMaxCard(CMemoryPool *, / mp
CExpressionHandle &exprhdl) const
{
/ contradictions produce no rows
if (exprhdl.DerivePropertyConstraint()->FContradiction())
{
return CMaxCard(0 /*ull*/);
}
return exprhdl.DeriveMaxCard(0);
}
/---------------------------------------------------------------------------
/ @function:
/ CLogicalDifference::PopCopyWithRemappedColumns
/
/ @doc:
/ Return a copy of the operator with remapped columns
/
/---------------------------------------------------------------------------
COperator *
CLogicalDifference::PopCopyWithRemappedColumns(CMemoryPool *mp,
UlongToColRefMap *colref_mapping,
BOOL must_exist)
{
CColRefArray *pdrgpcrOutput =
CUtils::PdrgpcrRemap(mp, m_pdrgpcrOutput, colref_mapping, must_exist);
CColRef2dArray *pdrgpdrgpcrInput = CUtils::PdrgpdrgpcrRemap(
mp, m_pdrgpdrgpcrInput, colref_mapping, must_exist);
return GPOS_NEW(mp) CLogicalDifference(mp, pdrgpcrOutput, pdrgpdrgpcrInput);
}
/---------------------------------------------------------------------------
/ @function:
/ CLogicalDifference::PxfsCandidates
/
/ @doc:
/ Get candidate xforms
/
/---------------------------------------------------------------------------
CXformSet *
CLogicalDifference::PxfsCandidates(CMemoryPool *mp) const
{
CXformSet *xform_set = GPOS_NEW(mp) CXformSet(mp);
(void) xform_set->ExchangeSet(CXform::ExfDifference2LeftAntiSemiJoin);
return xform_set;
}
/---------------------------------------------------------------------------
/ @function:
/ CLogicalDifference::PstatsDerive
/
/ @doc:
/ Derive statistics
/
/---------------------------------------------------------------------------
IStatistics *
CLogicalDifference::PstatsDerive(CMemoryPool *mp, CExpressionHandle &exprhdl,
IStatisticsArray * / not used
) const
{
GPOS_ASSERT(Esp(exprhdl) > EspNone);
/ difference is transformed into an aggregate over a LASJ,
/ we follow the same route to compute statistics
CColRefSetArray *output_colrefsets = GPOS_NEW(mp) CColRefSetArray(mp);
const ULONG size = m_pdrgpdrgpcrInput->Size();
for (ULONG ul = 0; ul < size; ul++)
{
CColRefSet *pcrs =
GPOS_NEW(mp) CColRefSet(mp, (*m_pdrgpdrgpcrInput)[ul]);
output_colrefsets->Append(pcrs);
}
IStatistics *outer_stats = exprhdl.Pstats(0);
IStatistics *inner_side_stats = exprhdl.Pstats(1);
/ construct the scalar condition for the LASJ
CExpression *pexprScCond =
CUtils::PexprConjINDFCond(mp, m_pdrgpdrgpcrInput);
/ compute the statistics for LASJ
CColRefSet *outer_refs = exprhdl.DeriveOuterReferences();
CStatsPredJoinArray *join_preds_stats =
CStatsPredUtils::ExtractJoinStatsFromExpr(mp, exprhdl, pexprScCond,
output_colrefsets, outer_refs,
true / is an LASJ
);
IStatistics *LASJ_stats =
outer_stats->CalcLASJoinStats(mp, inner_side_stats, join_preds_stats,
true /* DoIgnoreLASJHistComputation */
);
/ clean up
pexprScCond->Release();
join_preds_stats->Release();
/ computed columns
ULongPtrArray *pdrgpulComputedCols = GPOS_NEW(mp) ULongPtrArray(mp);
IStatistics *stats = CLogicalGbAgg::PstatsDerive(
mp, LASJ_stats,
(*m_pdrgpdrgpcrInput)[0], / we group by the columns of the first child
pdrgpulComputedCols, / no computed columns for set ops
nullptr / no keys, use all grouping cols
);
/ clean up
pdrgpulComputedCols->Release();
LASJ_stats->Release();
output_colrefsets->Release();
return stats;
}
/ EOF
相关信息
相关文章
greenplumn CExpressionFactorizer 源码
greenplumn CExpressionHandle 源码
greenplumn CExpressionPreprocessor 源码
greenplumn CExpressionUtils 源码