greenplumn CLogicalFullOuterJoin 代码
文件路径：/src/backend/gporca/libgpopt/include/gpopt/operators/CLogicalFullOuterJoin.h
/---------------------------------------------------------------------------
/ Greenplum Database
/ Copyright (C) 2013 EMC Corp.
/
/ @filename:
/ CLogicalFullOuterJoin.h
/
/ @doc:
/ Full outer join operator
/---------------------------------------------------------------------------
#ifndef GPOS_CLogicalFullOuterJoin_H
#define GPOS_CLogicalFullOuterJoin_H
#include "gpos/base.h"
#include "gpopt/operators/CLogicalJoin.h"
namespace gpopt
{
/---------------------------------------------------------------------------
/ @class:
/ CLogicalFullOuterJoin
/
/ @doc:
/ Full outer join operator
/
/---------------------------------------------------------------------------
class CLogicalFullOuterJoin : public CLogicalJoin
{
private:
public:
CLogicalFullOuterJoin(const CLogicalFullOuterJoin &) = delete;
/ ctor
explicit CLogicalFullOuterJoin(
CMemoryPool *mp, CXform::EXformId origin_xform = CXform::ExfSentinel);
/ dtor
~CLogicalFullOuterJoin() override = default;
/ ident accessors
EOperatorId
Eopid() const override
{
return EopLogicalFullOuterJoin;
}
/ return a string for operator name
const CHAR *
SzId() const override
{
return "CLogicalFullOuterJoin";
}
/ return true if we can pull projections up past this operator from its given child
BOOL FCanPullProjectionsUp(ULONG /child_index
) const override
{
return false;
}
/-------------------------------------------------------------------------------------
/ Derived Relational Properties
/-------------------------------------------------------------------------------------
/ derive not nullable output columns
CColRefSet *
DeriveNotNullColumns(CMemoryPool *mp,
CExpressionHandle & /exprhdl
) const override
{
/ all output columns are nullable
return GPOS_NEW(mp) CColRefSet(mp);
}
/ derive max card
CMaxCard DeriveMaxCard(CMemoryPool *mp,
CExpressionHandle &exprhdl) const override;
/ derive constraint property
CPropConstraint *
DerivePropertyConstraint(CMemoryPool *mp,
CExpressionHandle & /exprhdl
) const override
{
return GPOS_NEW(mp) CPropConstraint(
mp, GPOS_NEW(mp) CColRefSetArray(mp), nullptr /*pcnstr*/);
}
/ promise level for stat derivation
EStatPromise
Esp(CExpressionHandle & /exprhdl
) const override
{
/ Disable stats derivation for CLogicalFullOuterJoin because it is
/ currently not implemented. Instead rely on stats coming from the
/ equivalent UNION expression (formed using ExfExpandFullOuterJoin).
/ Also see CXformCTEAnchor2Sequence::Transform() and
/ CXformCTEAnchor2TrivialSelect::Transform().
return EspLow;
}
/-------------------------------------------------------------------------------------
/ Transformations
/-------------------------------------------------------------------------------------
/ candidate set of xforms
CXformSet *PxfsCandidates(CMemoryPool *mp) const override;
/-------------------------------------------------------------------------------------
/-------------------------------------------------------------------------------------
/-------------------------------------------------------------------------------------
/ conversion function
static CLogicalFullOuterJoin *
PopConvert(COperator *pop)
{
GPOS_ASSERT(nullptr != pop);
GPOS_ASSERT(EopLogicalFullOuterJoin == pop->Eopid());
return dynamic_cast<CLogicalFullOuterJoin *>(pop);
}
}; / class CLogicalFullOuterJoin
} / namespace gpopt
#endif / !GPOS_CLogicalFullOuterJoin_H
/ EOF
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