greenplumn CLogicalSelect 代码
文件路径：/src/backend/gporca/libgpopt/include/gpopt/operators/CLogicalSelect.h
/---------------------------------------------------------------------------
/ Greenplum Database
/ Copyright (C) 2011 EMC Corp.
/
/ @filename:
/ CLogicalSelect.h
/
/ @doc:
/ Select operator
/---------------------------------------------------------------------------
#ifndef GPOS_CLogicalSelect_H
#define GPOS_CLogicalSelect_H
#include "gpos/base.h"
#include "gpopt/operators/CExpressionHandle.h"
#include "gpopt/operators/CLogicalUnary.h"
namespace gpopt
{
using ExprPredToExprPredPartMap =
CHashMap<CExpression, CExpression, CExpression::HashValue, CUtils::Equals,
CleanupRelease<CExpression>, CleanupRelease<CExpression>>;
/---------------------------------------------------------------------------
/ @class:
/ CLogicalSelect
/
/ @doc:
/ Select operator
/
/---------------------------------------------------------------------------
class CLogicalSelect : public CLogicalUnary
{
private:
ExprPredToExprPredPartMap *m_phmPexprPartPred;
/ table descriptor
CTableDescriptor *m_ptabdesc;
public:
CLogicalSelect(const CLogicalSelect &) = delete;
/ ctor
explicit CLogicalSelect(CMemoryPool *mp);
/ ctor
CLogicalSelect(CMemoryPool *mp, CTableDescriptor *ptabdesc);
/ dtor
~CLogicalSelect() override;
/ ident accessors
EOperatorId
Eopid() const override
{
return EopLogicalSelect;
}
const CHAR *
SzId() const override
{
return "CLogicalSelect";
}
/ return table's descriptor
CTableDescriptor *
Ptabdesc() const
{
return m_ptabdesc;
}
/-------------------------------------------------------------------------------------
/ Derived Relational Properties
/-------------------------------------------------------------------------------------
/ derive output columns
CColRefSet *DeriveOutputColumns(CMemoryPool *,
CExpressionHandle &) override;
/ dervive keys
CKeyCollection *DeriveKeyCollection(
CMemoryPool *mp, CExpressionHandle &exprhdl) const override;
/ derive max card
CMaxCard DeriveMaxCard(CMemoryPool *mp,
CExpressionHandle &exprhdl) const override;
/ derive constraint property
CPropConstraint *
DerivePropertyConstraint(CMemoryPool *mp,
CExpressionHandle &exprhdl) const override
{
return PpcDeriveConstraintFromPredicates(mp, exprhdl);
}
/ derive table descriptor
CTableDescriptor *
DeriveTableDescriptor(CMemoryPool *, / mp
CExpressionHandle &exprhdl) const override
{
return exprhdl.DeriveTableDescriptor(0);
}
/ compute partition predicate to pass down to n-th child
CExpression *PexprPartPred(CMemoryPool *mp, CExpressionHandle &exprhdl,
CExpression *pexprInput,
ULONG child_index) const override;
/-------------------------------------------------------------------------------------
/ Transformations
/-------------------------------------------------------------------------------------
/ candidate set of xforms
CXformSet *PxfsCandidates(CMemoryPool *) const override;
/-------------------------------------------------------------------------------------
/-------------------------------------------------------------------------------------
/-------------------------------------------------------------------------------------
/ return true if operator can select a subset of input tuples based on some predicate,
BOOL
FSelectionOp() const override
{
return true;
}
/ conversion function
static CLogicalSelect *
PopConvert(COperator *pop)
{
GPOS_ASSERT(nullptr != pop);
GPOS_ASSERT(EopLogicalSelect == pop->Eopid());
return dynamic_cast<CLogicalSelect *>(pop);
}
/ derive statistics
IStatistics *PstatsDerive(CMemoryPool *mp, CExpressionHandle &exprhdl,
IStatisticsArray *stats_ctxt) const override;
}; / class CLogicalSelect
} / namespace gpopt
#endif / !GPOS_CLogicalSelect_H
/ EOF
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