greenplumn CXformSelect2Filter 源码
greenplumn CXformSelect2Filter 代码
文件路径：/src/backend/gporca/libgpopt/src/xforms/CXformSelect2Filter.cpp
//---------------------------------------------------------------------------
// Greenplum Database
// Copyright (C) 2011 EMC Corp.
//
// @filename:
// CXformSelect2Filter.cpp
//
// @doc:
// Implementation of transform
//---------------------------------------------------------------------------
#include "gpopt/xforms/CXformSelect2Filter.h"
#include "gpos/base.h"
#include "gpopt/operators/CLogicalSelect.h"
#include "gpopt/operators/CPatternLeaf.h"
#include "gpopt/operators/CPhysicalFilter.h"
using namespace gpopt;
//---------------------------------------------------------------------------
// @function:
// CXformSelect2Filter::CXformSelect2Filter
//
// @doc:
// Ctor
//
//---------------------------------------------------------------------------
CXformSelect2Filter::CXformSelect2Filter(CMemoryPool *mp)
: // pattern
CXformImplementation(GPOS_NEW(mp) CExpression(
mp, GPOS_NEW(mp) CLogicalSelect(mp),
GPOS_NEW(mp) CExpression(
mp, GPOS_NEW(mp) CPatternLeaf(mp)), // relational child
GPOS_NEW(mp)
CExpression(mp, GPOS_NEW(mp) CPatternLeaf(mp)) // predicate
))
{
}
//---------------------------------------------------------------------------
// @function:
// CXformSelect2Filter::Exfp
//
// @doc:
// Compute xform promise level for a given expression handle;
// if scalar predicate has a subquery, then we must have an
// equivalent logical Apply expression created during exploration;
// no need for generating a Filter expression here
//
//---------------------------------------------------------------------------
CXform::EXformPromise
CXformSelect2Filter::Exfp(CExpressionHandle &exprhdl) const
{
if (exprhdl.DeriveHasSubquery(1))
{
return CXform::ExfpNone;
}
return CXform::ExfpHigh;
}
//---------------------------------------------------------------------------
// @function:
// CXformSelect2Filter::Transform
//
// @doc:
// Actual transformation
//
//---------------------------------------------------------------------------
void
CXformSelect2Filter::Transform(CXformContext *pxfctxt, CXformResult *pxfres,
CExpression *pexpr) const
{
GPOS_ASSERT(nullptr != pxfctxt);
GPOS_ASSERT(FPromising(pxfctxt->Pmp(), this, pexpr));
GPOS_ASSERT(FCheckPattern(pexpr));
CMemoryPool *mp = pxfctxt->Pmp();
// extract components
CExpression *pexprRelational = (*pexpr)[0];
CExpression *pexprScalar = (*pexpr)[1];
// addref all children
pexprRelational->AddRef();
pexprScalar->AddRef();
// assemble physical operator
CExpression *pexprFilter = GPOS_NEW(mp) CExpression(
mp, GPOS_NEW(mp) CPhysicalFilter(mp), pexprRelational, pexprScalar);
// add alternative to results
pxfres->Add(pexprFilter);
}
// 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