//---------------------------------------------------------------------------
// @function:
// CLogicalSequenceProject::Matches
//
// @doc:
// Matching function
//
//---------------------------------------------------------------------------
BOOL
CLogicalSequenceProject::Matches
(
COperator *pop
)
const
{
GPOS_ASSERT(NULL != pop);
if (Eopid() == pop->Eopid())
{
CLogicalSequenceProject *popLogicalSequenceProject = CLogicalSequenceProject::PopConvert(pop);
return
m_pds->Matches(popLogicalSequenceProject->Pds()) &&
CWindowFrame::Equals(m_pdrgpwf, popLogicalSequenceProject->Pdrgpwf()) &&
COrderSpec::Equals(m_pdrgpos, popLogicalSequenceProject->Pdrgpos());
}
return false;
}
//---------------------------------------------------------------------------
// @function:
// CXformSubqueryUnnest::PexprSubqueryUnnest
//
// @doc:
// Helper for unnesting subquery under a given context
//
//---------------------------------------------------------------------------
CExpression *
CXformSubqueryUnnest::PexprSubqueryUnnest
(
IMemoryPool *pmp,
CExpression *pexpr,
BOOL fEnforceCorrelatedApply
)
{
GPOS_ASSERT(NULL != pexpr);
if (GPOS_FTRACE(EopttraceEnforceCorrelatedExecution) && !fEnforceCorrelatedApply)
{
// if correlated execution is enforced, we cannot generate an expression
// that does not use correlated Apply
return NULL;
}
// extract components
CExpression *pexprOuter = (*pexpr)[0];
CExpression *pexprScalar = (*pexpr)[1];
// we add-ref the logical child since the resulting expression must re-use it
pexprOuter->AddRef();
CExpression *pexprNewOuter = NULL;
CExpression *pexprResidualScalar = NULL;
CSubqueryHandler::ESubqueryCtxt esqctxt = CSubqueryHandler::EsqctxtFilter;
if (COperator::EopScalarProjectList == pexprScalar->Pop()->Eopid())
{
esqctxt = CSubqueryHandler::EsqctxtValue;
}
// calling the handler removes subqueries and sets new logical and scalar expressions
CSubqueryHandler sh(pmp, fEnforceCorrelatedApply);
if (!CSubqueryHandler::FProcess
(
sh,
pexprOuter,
pexprScalar,
false /* fDisjunctionOrNegation */,
esqctxt,
&pexprNewOuter,
&pexprResidualScalar
)
)
{
CRefCount::SafeRelease(pexprNewOuter);
CRefCount::SafeRelease(pexprResidualScalar);
return NULL;
}
// create a new alternative using the new logical and scalar expressions
CExpression *pexprResult = NULL;
if (CSubqueryHandler::EsqctxtFilter == esqctxt)
{
pexprResult = CUtils::PexprLogicalSelect(pmp, pexprNewOuter, pexprResidualScalar);
}
else
{
GPOS_ASSERT(CSubqueryHandler::EsqctxtValue == esqctxt);
CLogicalSequenceProject *popSeqPrj = NULL;
CLogicalGbAgg *popGbAgg = NULL;
COperator::EOperatorId eopid = pexpr->Pop()->Eopid();
switch (eopid)
{
case COperator::EopLogicalProject:
pexprResult = CUtils::PexprLogicalProject(pmp, pexprNewOuter, pexprResidualScalar, false /*fNewComputedCol*/);
break;
case COperator::EopLogicalGbAgg:
popGbAgg = CLogicalGbAgg::PopConvert(pexpr->Pop());
popGbAgg->Pdrgpcr()->AddRef();
pexprResult = CUtils::PexprLogicalGbAgg(pmp, popGbAgg->Pdrgpcr(), pexprNewOuter, pexprResidualScalar, popGbAgg->Egbaggtype());
break;
case COperator::EopLogicalSequenceProject:
popSeqPrj = CLogicalSequenceProject::PopConvert(pexpr->Pop());
popSeqPrj->Pds()->AddRef();
popSeqPrj->Pdrgpos()->AddRef();
popSeqPrj->Pdrgpwf()->AddRef();
pexprResult =
CUtils::PexprLogicalSequenceProject(pmp, popSeqPrj->Pds(), popSeqPrj->Pdrgpos(), popSeqPrj->Pdrgpwf(), pexprNewOuter, pexprResidualScalar);
break;
default:
GPOS_ASSERT(!"Unnesting subqueries for an invalid operator");
break;
}
}
// normalize resulting expression
CExpression *pexprNormalized = CNormalizer::PexprNormalize(pmp, pexprResult);
pexprResult->Release();
// pull up projections
CExpression *pexprPullUpProjections = CNormalizer::PexprPullUpProjections(pmp, pexprNormalized);
pexprNormalized->Release();
return pexprPullUpProjections;
}
