greenplumn CXformExpandNAryJoinMinCard 源码

  • 2022-08-18
  • 浏览 (4)

greenplumn CXformExpandNAryJoinMinCard 代码

文件路径:/src/backend/gporca/libgpopt/include/gpopt/xforms/CXformExpandNAryJoinMinCard.h

//---------------------------------------------------------------------------
//	Greenplum Database
//	Copyright (C) 2012 EMC Corp.
//
//	@filename:
//		CXformExpandNAryJoinMinCard.h
//
//	@doc:
//		Expand n-ary join into series of binary joins while minimizing
//		cardinality of intermediate results
//---------------------------------------------------------------------------
#ifndef GPOPT_CXformExpandNAryJoinMinCard_H
#define GPOPT_CXformExpandNAryJoinMinCard_H

#include "gpos/base.h"

#include "gpopt/xforms/CXformExploration.h"

namespace gpopt
{
using namespace gpos;

//---------------------------------------------------------------------------
//	@class:
//		CXformExpandNAryJoinMinCard
//
//	@doc:
//		Expand n-ary join into series of binary joins while minimizing
//		cardinality of intermediate results
//
//---------------------------------------------------------------------------
class CXformExpandNAryJoinMinCard : public CXformExploration
{
private:
public:
	CXformExpandNAryJoinMinCard(const CXformExpandNAryJoinMinCard &) = delete;

	// ctor
	explicit CXformExpandNAryJoinMinCard(CMemoryPool *mp);

	// dtor
	~CXformExpandNAryJoinMinCard() override = default;

	// ident accessors
	EXformId
	Exfid() const override
	{
		return ExfExpandNAryJoinMinCard;
	}

	// return a string for xform name
	const CHAR *
	SzId() const override
	{
		return "CXformExpandNAryJoinMinCard";
	}

	// compute xform promise for a given expression handle
	EXformPromise Exfp(CExpressionHandle &exprhdl) const override;

	// do stats need to be computed before applying xform?
	BOOL
	FNeedsStats() const override
	{
		return true;
	}

	// actual transform
	void Transform(CXformContext *pxfctxt, CXformResult *pxfres,
				   CExpression *pexpr) const override;

	BOOL
	IsApplyOnce() override
	{
		return true;
	}
};	// class CXformExpandNAryJoinMinCard

}  // namespace gpopt


#endif	// !GPOPT_CXformExpandNAryJoinMinCard_H

// EOF

相关信息

greenplumn 源码目录

相关文章

greenplumn CDecorrelator 源码

greenplumn CJoinOrder 源码

greenplumn CJoinOrderDP 源码

greenplumn CJoinOrderDPv2 源码

greenplumn CJoinOrderGreedy 源码

greenplumn CJoinOrderMinCard 源码

greenplumn CSubqueryHandler 源码

greenplumn CXform 源码

greenplumn CXformAntiSemiJoinAntiSemiJoinNotInSwap 源码

greenplumn CXformAntiSemiJoinAntiSemiJoinSwap 源码

0  赞