greenplumn CXformLeftSemiApply2LeftSemiJoin 源码
greenplumn CXformLeftSemiApply2LeftSemiJoin 代码
文件路径：/src/backend/gporca/libgpopt/src/xforms/CXformLeftSemiApply2LeftSemiJoin.cpp
//---------------------------------------------------------------------------
// Greenplum Database
// Copyright (C) 2012 EMC Corp.
//
// @filename:
// CXformLeftSemiApply2LeftSemiJoin.cpp
//
// @doc:
// Implementation of transform
//---------------------------------------------------------------------------
#include "gpopt/xforms/CXformLeftSemiApply2LeftSemiJoin.h"
#include "gpos/base.h"
using namespace gpopt;
//---------------------------------------------------------------------------
// @function:
// CXformLeftSemiApply2LeftSemiJoin::Exfp
//
// @doc:
// Compute xform promise for a given expression handle;
// outer references are not allowed
//
//---------------------------------------------------------------------------
CXform::EXformPromise
CXformLeftSemiApply2LeftSemiJoin::Exfp(CExpressionHandle &exprhdl) const
{
// if there are outer refs that include columns from the immediate outer child, the
// transformation is applicable
if (exprhdl.HasOuterRefs(1 /*child_index*/) &&
!CUtils::FInnerUsesExternalColsOnly(exprhdl))
{
return CXform::ExfpHigh;
}
return CXform::ExfpNone;
}
//---------------------------------------------------------------------------
// @function:
// CXformLeftSemiApply2LeftSemiJoin::Transform
//
// @doc:
// Actual transformation
//
//---------------------------------------------------------------------------
void
CXformLeftSemiApply2LeftSemiJoin::Transform(CXformContext *pxfctxt,
CXformResult *pxfres,
CExpression *pexpr) const
{
GPOS_ASSERT(nullptr != pxfctxt);
GPOS_ASSERT(FPromising(pxfctxt->Pmp(), this, pexpr));
GPOS_ASSERT(FCheckPattern(pexpr));
Decorrelate(pxfctxt, pxfres, pexpr);
}
// EOF
相关信息
相关文章
greenplumn CJoinOrderGreedy 源码
greenplumn CJoinOrderMinCard 源码
greenplumn CSubqueryHandler 源码
0
赞
热门推荐
-
2、 - 优质文章
-
3、 gate.io
-
7、 golang
-
9、 openharmony
-
10、 Vue中input框自动聚焦