greenplumn CPhysicalScan 代码
文件路径：/src/backend/gporca/libgpopt/include/gpopt/operators/CPhysicalScan.h
/---------------------------------------------------------------------------
/ Greenplum Database
/ Copyright (C) 2012 EMC Corp
/
/ @filename:
/ CPhysicalScan.h
/
/ @doc:
/ Base class for physical scan operators
/---------------------------------------------------------------------------
#ifndef GPOPT_CPhysicalScan_H
#define GPOPT_CPhysicalScan_H
#include "gpos/base.h"
#include "gpopt/base/CCTEMap.h"
#include "gpopt/base/CDistributionSpecHashed.h"
#include "gpopt/operators/CExpressionHandle.h"
#include "gpopt/operators/CPhysical.h"
namespace gpopt
{
/ fwd declarations
class CTableDescriptor;
class CName;
/---------------------------------------------------------------------------
/ @class:
/ CPhysicalScan
/
/ @doc:
/ Base class for physical scan operators
/
/---------------------------------------------------------------------------
class CPhysicalScan : public CPhysical
{
protected:
/ alias for table
const CName *m_pnameAlias;
/ table descriptor
CTableDescriptor *m_ptabdesc;
/ output columns
CColRefArray *m_pdrgpcrOutput;
/ distribution
CDistributionSpec *m_pds;
/ stats of base table -- used for costing
/ if operator is index scan, this is the stats of table on which index is created
IStatistics *m_pstatsBaseTable;
private:
/ compute stats of underlying table
void ComputeTableStats(CMemoryPool *mp);
/ search the given array of predicates for an equality predicate that has
/ one side equal to given expression
static CExpression *PexprMatchEqualitySide(
CExpression *pexprToMatch,
CExpressionArray *pdrgpexpr / array of predicates to inspect
);
/ private copy ctor
CPhysicalScan(const CPhysicalScan &);
public:
/ ctors
CPhysicalScan(CMemoryPool *mp, const CName *pname, CTableDescriptor *,
CColRefArray *colref_array);
/ dtor
~CPhysicalScan() override;
/ return table descriptor
virtual CTableDescriptor *
Ptabdesc() const
{
return m_ptabdesc;
}
/ output columns
virtual CColRefArray *
PdrgpcrOutput() const
{
return m_pdrgpcrOutput;
}
/ sensitivity to order of inputs
BOOL FInputOrderSensitive() const override;
/-------------------------------------------------------------------------------------
/ Required Plan Properties
/-------------------------------------------------------------------------------------
/ compute required output columns of the n-th child
CColRefSet *
PcrsRequired(CMemoryPool *, / mp
CExpressionHandle &, / exprhdl
CColRefSet *, / pcrsRequired
ULONG, / child_index
CDrvdPropArray *, / pdrgpdpCtxt
ULONG / ulOptReq
) override
{
GPOS_ASSERT(!"CPhysicalScan has no children");
return nullptr;
}
/ compute required ctes of the n-th child
CCTEReq *
PcteRequired(CMemoryPool *, /mp,
CExpressionHandle &, /exprhdl,
CCTEReq *, /pcter,
ULONG, /child_index,
CDrvdPropArray *, /pdrgpdpCtxt,
ULONG /ulOptReq
) const override
{
GPOS_ASSERT(!"CPhysicalScan has no children");
return nullptr;
}
/ compute required sort columns of the n-th child
COrderSpec *
PosRequired(CMemoryPool *, / mp
CExpressionHandle &, / exprhdl
COrderSpec *, / posRequired
ULONG, / child_index
CDrvdPropArray *, / pdrgpdpCtxt
ULONG / ulOptReq
) const override
{
GPOS_ASSERT(!"CPhysicalScan has no children");
return nullptr;
}
/ compute required distribution of the n-th child
CDistributionSpec *
PdsRequired(CMemoryPool *, / mp
CExpressionHandle &, / exprhdl
CDistributionSpec *, / pdsRequired
ULONG, / child_index
CDrvdPropArray *, / pdrgpdpCtxt
ULONG / ulOptReq
) const override
{
GPOS_ASSERT(!"CPhysicalScan has no children");
return nullptr;
}
/ compute required rewindability of the n-th child
CRewindabilitySpec *
PrsRequired(CMemoryPool *, /mp
CExpressionHandle &, /exprhdl
CRewindabilitySpec *, /prsRequired
ULONG, / child_index
CDrvdPropArray *, / pdrgpdpCtxt
ULONG / ulOptReq
) const override
{
GPOS_ASSERT(!"CPhysicalScan has no children");
return nullptr;
}
/ check if required columns are included in output columns
BOOL FProvidesReqdCols(CExpressionHandle &exprhdl, CColRefSet *pcrsRequired,
ULONG ulOptReq) const override;
/-------------------------------------------------------------------------------------
/ Derived Plan Properties
/-------------------------------------------------------------------------------------
/ derive sort order
COrderSpec *
PosDerive(CMemoryPool *mp,
CExpressionHandle & / exprhdl
) const override
{
/ return empty sort order
return GPOS_NEW(mp) COrderSpec(mp);
}
/ derive distribution
CDistributionSpec *PdsDerive(CMemoryPool *mp,
CExpressionHandle &exprhdl) const override;
/ derive cte map
CCTEMap *
PcmDerive(CMemoryPool *mp,
CExpressionHandle & /exprhdl
) const override
{
return GPOS_NEW(mp) CCTEMap(mp);
}
/ derive rewindability
CRewindabilitySpec *
PrsDerive(CMemoryPool *mp,
CExpressionHandle & / exprhdl
) const override
{
/ rewindability of output is always true
return GPOS_NEW(mp)
CRewindabilitySpec(CRewindabilitySpec::ErtRewindable,
CRewindabilitySpec::EmhtNoMotion);
}
/-------------------------------------------------------------------------------------
/ Enforced Properties
/-------------------------------------------------------------------------------------
/ return order property enforcing type for this operator
CEnfdProp::EPropEnforcingType EpetOrder(
CExpressionHandle &exprhdl, const CEnfdOrder *peo) const override;
/ return distribution property enforcing type for this operator
CEnfdProp::EPropEnforcingType EpetDistribution(
CExpressionHandle &exprhdl,
const CEnfdDistribution *ped) const override;
/ return rewindability property enforcing type for this operator
CEnfdProp::EPropEnforcingType
EpetRewindability(CExpressionHandle &, / exprhdl
const CEnfdRewindability * / per
) const override
{
/ no need for enforcing rewindability on output
return CEnfdProp::EpetUnnecessary;
}
/ return true if operator passes through stats obtained from children,
/ this is used when computing stats during costing
BOOL
FPassThruStats() const override
{
return false;
}
/ return true if operator is dynamic scan
virtual BOOL
FDynamicScan() const
{
return false;
}
/ stats of underlying table
IStatistics *
PstatsBaseTable() const
{
return m_pstatsBaseTable;
}
/ statistics derivation during costing
virtual IStatistics *PstatsDerive(CMemoryPool *mp,
CExpressionHandle &exprhdl,
CReqdPropPlan *prpplan,
IStatisticsArray *stats_ctxt) const = 0;
/ conversion function
static CPhysicalScan *PopConvert(COperator *pop);
}; / class CPhysicalScan
} / namespace gpopt
#endif / !GPOPT_CPhysicalScan_H
/ 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