//---------------------------------------------------------------------------
// @function:
// CGroupExpression::FCostContextExists
//
// @doc:
// Check if cost context already exists in group expression hash table
//
//---------------------------------------------------------------------------
BOOL
CGroupExpression::FCostContextExists
(
COptimizationContext *poc,
DrgPoc *pdrgpoc
)
{
GPOS_ASSERT(NULL != poc);
// lookup context based on required properties
CCostContext *pccFound = NULL;
{
ShtAcc shta(Sht(), poc);
pccFound = shta.PtLookup();
}
while (NULL != pccFound)
{
if (COptimizationContext::FEqualContextIds(pdrgpoc, pccFound->Pdrgpoc()))
{
// a cost context, matching required properties and child contexts, was already created
return true;
}
{
ShtAcc shta(Sht(), poc);
pccFound = shta.PtNext(pccFound);
}
}
return false;
}
//---------------------------------------------------------------------------
// @function:
// COptimizationContext::PrppCTEProducer
//
// @doc:
// Compute required properties to CTE producer based on plan properties
// of CTE consumer
//
//---------------------------------------------------------------------------
CReqdPropPlan *
COptimizationContext::PrppCTEProducer
(
IMemoryPool *mp,
COptimizationContext *poc,
ULONG ulSearchStages
)
{
GPOS_ASSERT(NULL != poc);
GPOS_ASSERT(NULL != poc->PccBest());
CCostContext *pccBest = poc->PccBest();
CGroupExpression *pgexpr = pccBest->Pgexpr();
BOOL fOptimizeCTESequence =
(
COperator::EopPhysicalSequence == pgexpr->Pop()->Eopid() &&
(*pgexpr)[0]->FHasCTEProducer()
);
if (!fOptimizeCTESequence)
{
// best group expression is not a CTE sequence
return NULL;
}
COptimizationContext *pocProducer = (*pgexpr)[0]->PocLookupBest(mp, ulSearchStages, (*pccBest->Pdrgpoc())[0]->Prpp());
if (NULL == pocProducer)
{
return NULL;
}
CCostContext *pccProducer = pocProducer->PccBest();
if (NULL == pccProducer)
{
return NULL;
}
COptimizationContext *pocConsumer = (*pgexpr)[1]->PocLookupBest(mp, ulSearchStages, (*pccBest->Pdrgpoc())[1]->Prpp());
if (NULL == pocConsumer)
{
return NULL;
}
CCostContext *pccConsumer = pocConsumer->PccBest();
if (NULL == pccConsumer)
{
return NULL;
}
CColRefSet *pcrsInnerOutput = CDrvdPropRelational::GetRelationalProperties((*pgexpr)[1]->Pdp())->PcrsOutput();
CPhysicalCTEProducer *popProducer = CPhysicalCTEProducer::PopConvert(pccProducer->Pgexpr()->Pop());
UlongToColRefMap *colref_mapping = COptCtxt::PoctxtFromTLS()->Pcteinfo()->PhmulcrConsumerToProducer(mp, popProducer->UlCTEId(), pcrsInnerOutput, popProducer->Pdrgpcr());
CReqdPropPlan *prppProducer = CReqdPropPlan::PrppRemap(mp, pocProducer->Prpp(), pccConsumer->Pdpplan(), colref_mapping);
colref_mapping->Release();
if (prppProducer->Equals(pocProducer->Prpp()))
{
prppProducer->Release();
return NULL;
}
return prppProducer;
}