greenplumn CLogicalFullOuterJoin 源码

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

相关信息

greenplumn 源码目录

相关文章

greenplumn CExpression 源码

greenplumn CExpressionFactorizer 源码

greenplumn CExpressionHandle 源码

greenplumn CExpressionPreprocessor 源码

greenplumn CExpressionUtils 源码

greenplumn CHashedDistributions 源码

greenplumn CLogical 源码

greenplumn CLogicalApply 源码

greenplumn CLogicalAssert 源码

greenplumn CLogicalBitmapTableGet 源码