本文整理汇总了C++中CExpression::PdrgPexpr方法的典型用法代码示例。如果您正苦于以下问题：C++ CExpression::PdrgPexpr方法的具体用法？C++ CExpression::PdrgPexpr怎么用？C++ CExpression::PdrgPexpr使用的例子？那么, 这里精选的方法代码示例或许可以为您提供帮助。您也可以进一步了解该方法所在类CExpression的用法示例。
在下文中一共展示了CExpression::PdrgPexpr方法的2个代码示例，这些例子默认根据受欢迎程度排序。您可以为喜欢或者感觉有用的代码点赞，您的评价将有助于系统推荐出更棒的C++代码示例。
示例1: DrgPdrgPexpr
//---------------------------------------------------------------------------
// @function:
// CCNFConverter::Pdrgpdrgpexpr
//
// @doc:
// Create an array of arrays each holding the children of an expression
// from the given array
//
//
//---------------------------------------------------------------------------
DrgPdrgPexpr *
CCNFConverter::Pdrgpdrgpexpr
(
IMemoryPool *pmp,
DrgPexpr *pdrgpexpr
)
{
GPOS_ASSERT(NULL != pmp);
GPOS_ASSERT(NULL != pdrgpexpr);
DrgPdrgPexpr *pdrgpdrgpexpr = GPOS_NEW(pmp) DrgPdrgPexpr(pmp);
const ULONG ulArity = pdrgpexpr->UlLength();
for (ULONG ul = 0; ul < ulArity; ul++)
{
CExpression *pexpr = (*pdrgpexpr)[ul];
DrgPexpr *pdrgpexprChild = NULL;
if (CPredicateUtils::FAnd(pexpr))
{
pdrgpexprChild = pexpr->PdrgPexpr();
pdrgpexprChild->AddRef();
}
else
{
pdrgpexprChild = GPOS_NEW(pmp) DrgPexpr(pmp);
pexpr->AddRef();
pdrgpexprChild->Append(pexpr);
}
pdrgpdrgpexpr->Append(pdrgpexprChild);
}
return pdrgpdrgpexpr;
}示例2: exprhdl
//---------------------------------------------------------------------------
// @function:
// CNormalizer::PexprPullUpAndCombineProjects
//
// @doc:
// Pulls up logical projects as far as possible, and combines consecutive
// projects if possible
//
//---------------------------------------------------------------------------
CExpression *
CNormalizer::PexprPullUpAndCombineProjects
(
IMemoryPool *pmp,
CExpression *pexpr,
BOOL *pfSuccess // output to indicate whether anything was pulled up
)
{
GPOS_ASSERT(NULL != pexpr);
GPOS_ASSERT(NULL != pfSuccess);
COperator *pop = pexpr->Pop();
const ULONG ulArity = pexpr->UlArity();
if (!pop->FLogical() || 0 == ulArity)
{
pexpr->AddRef();
return pexpr;
}
DrgPexpr *pdrgpexprChildren = GPOS_NEW(pmp) DrgPexpr(pmp);
DrgPexpr *pdrgpexprPrElPullUp = GPOS_NEW(pmp) DrgPexpr(pmp);
CExpressionHandle exprhdl(pmp);
exprhdl.Attach(pexpr);
CColRefSet *pcrsOutput = CDrvdPropRelational::Pdprel(pexpr->PdpDerive())->PcrsOutput();
// extract the columns used by the scalar expression and the operator itself (for grouping, sorting, etc.)
CColRefSet *pcrsUsed = exprhdl.PcrsUsedColumns(pmp);
for (ULONG ul = 0; ul < ulArity; ul++)
{
CExpression *pexprChild = PexprPullUpAndCombineProjects(pmp, (*pexpr)[ul], pfSuccess);
if (pop->FLogical() && CLogical::PopConvert(pop)->FCanPullProjectionsUp(ul) &&
COperator::EopLogicalProject == pexprChild->Pop()->Eopid())
{
// this child is a project - see if any project elements can be pulled up
CExpression *pexprNewChild = PexprPullUpProjectElements
(
pmp,
pexprChild,
pcrsUsed,
pcrsOutput,
&pdrgpexprPrElPullUp
);
pexprChild->Release();
pexprChild = pexprNewChild;
}
pdrgpexprChildren->Append(pexprChild);
}
pcrsUsed->Release();
pop->AddRef();
if (0 < pdrgpexprPrElPullUp->UlLength() && COperator::EopLogicalProject == pop->Eopid())
{
// some project elements have been pulled up and the original expression
// was a project - combine its project list with the pulled up project elements
GPOS_ASSERT(2 == pdrgpexprChildren->UlLength());
*pfSuccess = true;
CExpression *pexprRelational = (*pdrgpexprChildren)[0];
CExpression *pexprPrLOld = (*pdrgpexprChildren)[1];
pexprRelational->AddRef();
CUtils::AddRefAppend(pdrgpexprPrElPullUp, pexprPrLOld->PdrgPexpr());
pdrgpexprChildren->Release();
CExpression *pexprPrjList = GPOS_NEW(pmp) CExpression(pmp, GPOS_NEW(pmp) CScalarProjectList(pmp), pdrgpexprPrElPullUp);
GPOS_ASSERT(CDrvdPropRelational::Pdprel(pexprRelational->PdpDerive())->PcrsOutput()->FSubset(CDrvdPropScalar::Pdpscalar(pexprPrjList->PdpDerive())->PcrsUsed()));
return GPOS_NEW(pmp) CExpression(pmp, pop, pexprRelational, pexprPrjList);
}
CExpression *pexprOutput = GPOS_NEW(pmp) CExpression(pmp, pop, pdrgpexprChildren);
if (0 == pdrgpexprPrElPullUp->UlLength())
{
// no project elements were pulled up
pdrgpexprPrElPullUp->Release();
return pexprOutput;
}
// some project elements were pulled - add a project on top of output expression
*pfSuccess = true;
CExpression *pexprPrjList = GPOS_NEW(pmp) CExpression(pmp, GPOS_NEW(pmp) CScalarProjectList(pmp), pdrgpexprPrElPullUp);
GPOS_ASSERT(CDrvdPropRelational::Pdprel(pexprOutput->PdpDerive())->PcrsOutput()->FSubset(CDrvdPropScalar::Pdpscalar(pexprPrjList->PdpDerive())->PcrsUsed()));
return GPOS_NEW(pmp) CExpression(pmp, GPOS_NEW(pmp) CLogicalProject(pmp), pexprOutput, pexprPrjList);
}