greenplumn CXformLeftSemiApplyWithExternalCorrs2InnerJoin 代码
文件路径：/src/backend/gporca/libgpopt/include/gpopt/xforms/CXformLeftSemiApplyWithExternalCorrs2InnerJoin.h
/---------------------------------------------------------------------------
/ Greenplum Database
/ Copyright (C) 2013 EMC Corp.
/
/ @filename:
/ CXformLeftSemiApplyWithExternalCorrs2InnerJoin.h
/
/ @doc:
/ Turn LS apply with external correlations apply into inner join;
/ external correlations are correlations in the inner child of LSA
/ that use columns not defined by the outer child of LSA
/---------------------------------------------------------------------------
#ifndef GPOPT_CXformLeftSemiApplyWithExternalCorrs2InnerJoin_H
#define GPOPT_CXformLeftSemiApplyWithExternalCorrs2InnerJoin_H
#include "gpos/base.h"
#include "gpopt/operators/CLogicalInnerJoin.h"
#include "gpopt/operators/CLogicalLeftSemiApply.h"
#include "gpopt/xforms/CXformApply2Join.h"
#include "gpopt/xforms/CXformUtils.h"
namespace gpopt
{
using namespace gpos;
/---------------------------------------------------------------------------
/ @class:
/ CXformLeftSemiApplyWithExternalCorrs2InnerJoin
/
/ @doc:
/ Transform Apply into Join by decorrelating the inner side
/
/---------------------------------------------------------------------------
class CXformLeftSemiApplyWithExternalCorrs2InnerJoin
: public CXformApply2Join<CLogicalLeftSemiApply, CLogicalInnerJoin>
{
private:
/ helper for splitting correlations into external and residual
static BOOL FSplitCorrelations(CMemoryPool *mp, CExpression *pexprOuter,
CExpression *pexprInner,
CExpressionArray *pdrgpexprAllCorr,
CExpressionArray **ppdrgpexprExternal,
CExpressionArray **ppdrgpexprResidual,
CColRefSet **ppcrsInnerUsed);
/ helper for collecting correlations
static BOOL FDecorrelate(CMemoryPool *mp, CExpression *pexpr,
CExpression **ppexprInnerNew,
CExpressionArray **ppdrgpexprCorr);
/ decorrelate semi apply with external correlations
static CExpression *PexprDecorrelate(CMemoryPool *mp, CExpression *pexpr);
public:
CXformLeftSemiApplyWithExternalCorrs2InnerJoin(
const CXformLeftSemiApplyWithExternalCorrs2InnerJoin &) = delete;
/ ctor
explicit CXformLeftSemiApplyWithExternalCorrs2InnerJoin(CMemoryPool *mp)
: CXformApply2Join<CLogicalLeftSemiApply, CLogicalInnerJoin>(
mp, true /*fDeepTree*/)
{
}
/ ctor with a passed pattern
CXformLeftSemiApplyWithExternalCorrs2InnerJoin(CMemoryPool *mp,
CExpression *pexprPattern)
: CXformApply2Join<CLogicalLeftSemiApply, CLogicalInnerJoin>(
mp, pexprPattern)
{
}
/ dtor
~CXformLeftSemiApplyWithExternalCorrs2InnerJoin() override = default;
/ ident accessors
EXformId
Exfid() const override
{
return ExfLeftSemiApplyWithExternalCorrs2InnerJoin;
}
const CHAR *
SzId() const override
{
return "CXformLeftSemiApplyWithExternalCorrs2InnerJoin";
}
/ compute xform promise for a given expression handle
EXformPromise Exfp(CExpressionHandle &exprhdl) const override;
/ actual transform
void Transform(CXformContext *pxfctxt, CXformResult *pxfres,
CExpression *pexpr) const override;
}; / class CXformLeftSemiApplyWithExternalCorrs2InnerJoin
} / namespace gpopt
#endif / !GPOPT_CXformLeftSemiApplyWithExternalCorrs2InnerJoin_H
/ EOF
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