greenplumn CXformExpandNAryJoinGreedy 源码

  • 2022-08-18
  • 浏览 (11)

greenplumn CXformExpandNAryJoinGreedy 代码

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

//---------------------------------------------------------------------------
//	Greenplum Database
//	Copyright (C) 2018 VMware, Inc. or its affiliates.
//
//	@filename:
//		CXformExpandNAryJoinGreedy.h
//
//	@doc:
//		Expand n-ary join into series of binary joins while minimizing
//		cardinality of intermediate results and delay cross joins to
//		the end
//---------------------------------------------------------------------------
#ifndef GPOPT_CXformExpandNAryJoinGreedy_H
#define GPOPT_CXformExpandNAryJoinGreedy_H

#include "gpos/base.h"

#include "gpopt/xforms/CXformExploration.h"

namespace gpopt
{
using namespace gpos;

//---------------------------------------------------------------------------
//	@class:
//		CXformExpandNAryJoinGreedy
//
//	@doc:
//		Expand n-ary join into series of binary joins while minimizing
//		cardinality of intermediate results and delay cross joins to
//		the end
//
//---------------------------------------------------------------------------
class CXformExpandNAryJoinGreedy : public CXformExploration
{
private:
public:
	CXformExpandNAryJoinGreedy(const CXformExpandNAryJoinGreedy &) = delete;

	// ctor
	explicit CXformExpandNAryJoinGreedy(CMemoryPool *pmp);

	// dtor
	~CXformExpandNAryJoinGreedy() override = default;

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

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

	// 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 CXformExpandNAryJoinGreedy

}  // namespace gpopt


#endif	// !GPOPT_CXformExpandNAryJoinGreedy_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