greenplumn CDefaultComparator 代码
文件路径：/src/backend/gporca/libgpopt/include/gpopt/base/CDefaultComparator.h
/---------------------------------------------------------------------------
/ Greenplum Database
/ Copyright (C) 2014 VMware, Inc. or its affiliates.
/
/ @filename:
/ CDefaultComparator.h
/
/ @doc:
/ Default comparator for IDatum instances
/
/ @owner:
/
/
/ @test:
/
/---------------------------------------------------------------------------
#ifndef GPOPT_CDefaultComparator_H
#define GPOPT_CDefaultComparator_H
#include "gpos/base.h"
#include "gpopt/base/IComparator.h"
#include "naucrates/md/IMDType.h"
#include "naucrates/traceflags/traceflags.h"
namespace gpmd
{
/ fwd declarations
class IMDId;
} / namespace gpmd
namespace gpnaucrates
{
/ fwd declarations
class IDatum;
} / namespace gpnaucrates
namespace gpopt
{
using namespace gpmd;
using namespace gpnaucrates;
using namespace gpos;
/ fwd declarations
class IConstExprEvaluator;
/---------------------------------------------------------------------------
/ @class:
/ CDefaultComparator
/
/ @doc:
/ Default comparator for IDatum instances. It is a singleton accessed
/ via CompGetInstance.
/
/---------------------------------------------------------------------------
class CDefaultComparator : public IComparator
{
private:
/ constant expression evaluator
IConstExprEvaluator *m_pceeval;
/ construct a comparison expression from the given components and evaluate it
BOOL FEvalComparison(CMemoryPool *mp, const IDatum *datum1,
const IDatum *datum2,
IMDType::ECmpType cmp_type) const;
/ return true iff we should use the internal (stats-based) evaluation
static BOOL FUseInternalEvaluator(const IDatum *datum1,
const IDatum *datum2,
BOOL *can_use_external_evaluator);
public:
CDefaultComparator(const CDefaultComparator &) = delete;
/ ctor
CDefaultComparator(IConstExprEvaluator *pceeval);
/ dtor
~CDefaultComparator() override = default;
/ tests if the two arguments are equal
BOOL Equals(const IDatum *datum1, const IDatum *datum2) const override;
/ tests if the first argument is less than the second
BOOL IsLessThan(const IDatum *datum1, const IDatum *datum2) const override;
/ tests if the first argument is less or equal to the second
BOOL IsLessThanOrEqual(const IDatum *datum1,
const IDatum *datum2) const override;
/ tests if the first argument is greater than the second
BOOL IsGreaterThan(const IDatum *datum1,
const IDatum *datum2) const override;
/ tests if the first argument is greater or equal to the second
BOOL IsGreaterThanOrEqual(const IDatum *datum1,
const IDatum *datum2) const override;
}; / CDefaultComparator
} / namespace gpopt
#endif / !CDefaultComparator_H
/ EOF
相关信息
相关文章
greenplumn CColConstraintsArrayMapper 源码