//---------------------------------------------------------------------------
// @function:
// CPhysical::GetSkew
//
// @doc:
// Helper to compute skew estimate based on given stats and
// distribution spec
//
//---------------------------------------------------------------------------
CDouble
CPhysical::GetSkew
(
IStatistics *stats,
CDistributionSpec *pds
)
{
CDouble dSkew = 1.0;
if (CDistributionSpec::EdtHashed == pds->Edt())
{
CDistributionSpecHashed *pdshashed = CDistributionSpecHashed::PdsConvert(pds);
const CExpressionArray *pdrgpexpr = pdshashed->Pdrgpexpr();
const ULONG size = pdrgpexpr->Size();
for (ULONG ul = 0; ul < size; ul++)
{
CExpression *pexpr = (*pdrgpexpr)[ul];
if (COperator::EopScalarIdent == pexpr->Pop()->Eopid())
{
// consider only hashed distribution direct columns for now
CScalarIdent *popScId = CScalarIdent::PopConvert(pexpr->Pop());
ULONG colid = popScId->Pcr()->Id();
CDouble dSkewCol = stats->GetSkew(colid);
if (dSkewCol > dSkew)
{
dSkew = dSkewCol;
}
}
}
}
return CDouble(dSkew);
}
//---------------------------------------------------------------------------
// @function:
// CStatsPredUtils::PstatspredLikeHandleCasting
//
// @doc:
// Create a LIKE statistics filter
//---------------------------------------------------------------------------
CStatsPred *
CStatsPredUtils::PstatspredLike
(
IMemoryPool *pmp,
CExpression *pexprPred,
CColRefSet *//pcrsOuterRefs,
)
{
GPOS_ASSERT(NULL != pexprPred);
GPOS_ASSERT(CPredicateUtils::FLikePredicate(pexprPred));
CExpression *pexprLeft = (*pexprPred)[0];
CExpression *pexprRight = (*pexprPred)[1];
// we support LIKE predicate of the following patterns
// CAST(ScIdent) LIKE Const
// CAST(ScIdent) LIKE CAST(Const)
// ScIdent LIKE Const
// ScIdent LIKE CAST(Const)
// CAST(Const) LIKE ScIdent
// CAST(Const) LIKE CAST(ScIdent)
// const LIKE ScIdent
// const LIKE CAST(ScIdent)
CExpression *pexprScIdent = NULL;
CExpression *pexprScConst = NULL;
CPredicateUtils::ExtractLikePredComponents(pexprPred, &pexprScIdent, &pexprScConst);
if (NULL == pexprScIdent || NULL == pexprScConst)
{
return GPOS_NEW(pmp) CStatsPredUnsupported(ULONG_MAX, CStatsPred::EstatscmptLike);
}
CScalarIdent *popScalarIdent = CScalarIdent::PopConvert(pexprScIdent->Pop());
ULONG ulColId = popScalarIdent->Pcr()->UlId();
CScalarConst *popScalarConst = CScalarConst::PopConvert(pexprScConst->Pop());
IDatum *pdatumLiteral = popScalarConst->Pdatum();
const CColRef *pcr = popScalarIdent->Pcr();
if (!IMDType::FStatsComparable(pcr->Pmdtype(), pdatumLiteral))
{
// unsupported stats comparison between the column and datum
return GPOS_NEW(pmp) CStatsPredUnsupported(pcr->UlId(), CStatsPred::EstatscmptLike);
}
CDouble dDefaultScaleFactor(1.0);
if (pdatumLiteral->FSupportLikePredicate())
{
dDefaultScaleFactor = pdatumLiteral->DLikePredicateScaleFactor();
}
pexprLeft->AddRef();
pexprRight->AddRef();
return GPOS_NEW(pmp) CStatsPredLike(ulColId, pexprLeft, pexprRight, dDefaultScaleFactor);
}
//---------------------------------------------------------------------------
// @function:
// CConstraint::PcnstrFromScalarCmp
//
// @doc:
// Create constraint from scalar comparison
//
//---------------------------------------------------------------------------
CConstraint *
CConstraint::PcnstrFromScalarCmp
(
IMemoryPool *pmp,
CExpression *pexpr,
DrgPcrs **ppdrgpcrs // output equivalence classes
)
{
GPOS_ASSERT(NULL != pexpr);
GPOS_ASSERT(CUtils::FScalarCmp(pexpr));
GPOS_ASSERT(NULL != ppdrgpcrs);
GPOS_ASSERT(NULL == *ppdrgpcrs);
CExpression *pexprLeft = (*pexpr)[0];
CExpression *pexprRight = (*pexpr)[1];
// check if the scalar comparison is over scalar idents
if (COperator::EopScalarIdent == pexprLeft->Pop()->Eopid()
&& COperator::EopScalarIdent == pexprRight->Pop()->Eopid())
{
CScalarIdent *popScIdLeft = CScalarIdent::PopConvert((*pexpr)[0]->Pop());
const CColRef *pcrLeft = popScIdLeft->Pcr();
CScalarIdent *popScIdRight = CScalarIdent::PopConvert((*pexpr)[1]->Pop());
const CColRef *pcrRight = popScIdRight->Pcr();
if (!CUtils::FConstrainableType(pcrLeft->Pmdtype()->Pmdid()) ||
!CUtils::FConstrainableType(pcrRight->Pmdtype()->Pmdid()))
{
return NULL;
}
*ppdrgpcrs = GPOS_NEW(pmp) DrgPcrs(pmp);
if (CPredicateUtils::FEquality(pexpr))
{
// col1 = col2
CColRefSet *pcrsNew = GPOS_NEW(pmp) CColRefSet(pmp);
pcrsNew->Include(pcrLeft);
pcrsNew->Include(pcrRight);
(*ppdrgpcrs)->Append(pcrsNew);
}
// create NOT NULL constraints to both columns
DrgPcnstr *pdrgpcnstr = GPOS_NEW(pmp) DrgPcnstr(pmp);
pdrgpcnstr->Append(CConstraintInterval::PciUnbounded(pmp, pcrLeft, false /*fIncludesNull*/));
pdrgpcnstr->Append(CConstraintInterval::PciUnbounded(pmp, pcrRight, false /*fIncludesNull*/));
return CConstraint::PcnstrConjunction(pmp, pdrgpcnstr);
}
// TODO: , May 28, 2012; add support for other cases besides (col cmp col)
return NULL;
}
//---------------------------------------------------------------------------
// @function:
// CConstraint::PcnstrFromScalarArrayCmp
//
// @doc:
// Create constraint from scalar array comparison expression
//
//---------------------------------------------------------------------------
CConstraint *
CConstraint::PcnstrFromScalarArrayCmp
(
IMemoryPool *pmp,
CExpression *pexpr,
CColRef *pcr
)
{
GPOS_ASSERT(NULL != pexpr);
GPOS_ASSERT(CUtils::FScalarArrayCmp(pexpr));
CScalarArrayCmp *popScArrayCmp = CScalarArrayCmp::PopConvert(pexpr->Pop());
CScalarArrayCmp::EArrCmpType earrccmpt = popScArrayCmp->Earrcmpt();
if ((CScalarArrayCmp::EarrcmpAny == earrccmpt || CScalarArrayCmp::EarrcmpAll == earrccmpt) &&
CPredicateUtils::FCompareIdentToConstArray(pexpr))
{
// column
#ifdef GPOS_DEBUG
CScalarIdent *popScId = CScalarIdent::PopConvert((*pexpr)[0]->Pop());
GPOS_ASSERT (pcr == (CColRef *) popScId->Pcr());
#endif // GPOS_DEBUG
// get comparison type
IMDType::ECmpType ecmpt = CUtils::Ecmpt(popScArrayCmp->PmdidOp());
CExpression *pexprArray = (*pexpr)[1];
DrgPcnstr *pdrgpcnstr = GPOS_NEW(pmp) DrgPcnstr(pmp);
const ULONG ulArity = pexprArray->UlArity();
for (ULONG ul = 0; ul < ulArity; ul++)
{
GPOS_ASSERT(CUtils::FScalarConst((*pexprArray)[ul]) && "expecting a constant");
CScalarConst *popScConst = CScalarConst::PopConvert((*pexprArray)[ul]->Pop());
CConstraintInterval *pci = CConstraintInterval::PciIntervalFromColConstCmp(pmp, pcr, ecmpt, popScConst);
pdrgpcnstr->Append(pci);
}
if (earrccmpt == CScalarArrayCmp::EarrcmpAny)
{
// predicate is of the form 'A IN (1,2,3)'
// return a disjunction of ranges {[1,1], [2,2], [3,3]}
return GPOS_NEW(pmp) CConstraintDisjunction(pmp, pdrgpcnstr);
}
// predicate is of the form 'A NOT IN (1,2,3)'
// return a conjunctive negation on {[1,1], [2,2], [3,3]}
return GPOS_NEW(pmp) CConstraintConjunction(pmp, pdrgpcnstr);
}
return NULL;
}
//---------------------------------------------------------------------------
// @function:
// CStatsPredUtils::PstatspredBoolean
//
// @doc:
// Extract statistics filtering information from boolean predicate
// in the form of scalar id or negated scalar id
//---------------------------------------------------------------------------
CStatsPred *
CStatsPredUtils::PstatspredBoolean
(
IMemoryPool *pmp,
CExpression *pexprPred,
CColRefSet * //pcrsOuterRefs
)
{
GPOS_ASSERT(NULL != pexprPred);
GPOS_ASSERT(CPredicateUtils::FBooleanScalarIdent(pexprPred) || CPredicateUtils::FNegatedBooleanScalarIdent(pexprPred));
COperator *pop = pexprPred->Pop();
CMDAccessor *pmda = COptCtxt::PoctxtFromTLS()->Pmda();
IDatum *pdatum = NULL;
ULONG ulColId = ULONG_MAX;
if (CPredicateUtils::FBooleanScalarIdent(pexprPred))
{
CScalarIdent *popScIdent = CScalarIdent::PopConvert(pop);
pdatum = pmda->PtMDType<IMDTypeBool>()->PdatumBool(pmp, true /* fValue */, false /* fNull */);
ulColId = popScIdent->Pcr()->UlId();
}
else
{
CExpression *pexprChild = (*pexprPred)[0];
pdatum = pmda->PtMDType<IMDTypeBool>()->PdatumBool(pmp, false /* fValue */, false /* fNull */);
ulColId = CScalarIdent::PopConvert(pexprChild->Pop())->Pcr()->UlId();
}
if (!pdatum->FStatsComparable(pdatum))
{
// stats calculations on such datums unsupported
pdatum->Release();
return GPOS_NEW(pmp) CStatsPredUnsupported(ulColId, CStatsPred::EstatscmptEq);
}
GPOS_ASSERT(NULL != pdatum && ULONG_MAX != ulColId);
return GPOS_NEW(pmp) CStatsPredPoint(ulColId, CStatsPred::EstatscmptEq, GPOS_NEW(pmp) CPoint(pdatum));
}
//---------------------------------------------------------------------------
// @function:
// CStatsPredUtils::PstatspredNullTest
//
// @doc:
// Extract statistics filtering information from a null test
//---------------------------------------------------------------------------
CStatsPred *
CStatsPredUtils::PstatspredNullTest
(
IMemoryPool *pmp,
CExpression *pexprPred,
CColRefSet * //pcrsOuterRefs
)
{
GPOS_ASSERT(NULL != pexprPred);
GPOS_ASSERT(FScalarIdentIsNull(pexprPred) || FScalarIdentIsNotNull(pexprPred));
CExpression *pexprNullTest = pexprPred;
CStatsPred::EStatsCmpType escmpt = CStatsPred::EstatscmptEq; // 'is null'
if (FScalarIdentIsNotNull(pexprPred))
{
pexprNullTest = (*pexprPred)[0];
escmpt = CStatsPred::EstatscmptNEq; // 'is not null'
}
CScalarIdent *popScalarIdent = CScalarIdent::PopConvert((*pexprNullTest)[0]->Pop());
const CColRef *pcr = popScalarIdent->Pcr();
IDatum *pdatum = CStatisticsUtils::PdatumNull(pcr);
if (!pdatum->FStatsComparable(pdatum))
{
// stats calculations on such datums unsupported
pdatum->Release();
return GPOS_NEW(pmp) CStatsPredUnsupported(pcr->UlId(), escmpt);
}
CPoint *ppoint = GPOS_NEW(pmp) CPoint(pdatum);
CStatsPredPoint *pstatspred = GPOS_NEW(pmp) CStatsPredPoint(pcr->UlId(), escmpt, ppoint);
return pstatspred;
}
//---------------------------------------------------------------------------
// @function:
// CConstraint::PcnstrFromScalarArrayCmp
//
// @doc:
// Create constraint from scalar array comparison expression
//
//---------------------------------------------------------------------------
CConstraint *
CConstraint::PcnstrFromScalarArrayCmp
(
IMemoryPool *pmp,
CExpression *pexpr,
CColRef *pcr
)
{
GPOS_ASSERT(NULL != pexpr);
GPOS_ASSERT(CUtils::FScalarArrayCmp(pexpr));
CScalarArrayCmp *popScArrayCmp = CScalarArrayCmp::PopConvert(pexpr->Pop());
CScalarArrayCmp::EArrCmpType earrccmpt = popScArrayCmp->Earrcmpt();
if ((CScalarArrayCmp::EarrcmpAny == earrccmpt || CScalarArrayCmp::EarrcmpAll == earrccmpt) &&
CPredicateUtils::FCompareIdentToConstArray(pexpr))
{
// column
#ifdef GPOS_DEBUG
CScalarIdent *popScId = CScalarIdent::PopConvert((*pexpr)[0]->Pop());
GPOS_ASSERT (pcr == (CColRef *) popScId->Pcr());
#endif // GPOS_DEBUG
// get comparison type
IMDType::ECmpType ecmpt = CUtils::Ecmpt(popScArrayCmp->PmdidOp());
CExpression *pexprArray = CUtils::PexprScalarArrayChild(pexpr);
const ULONG ulArity = CUtils::UlScalarArrayArity(pexprArray);
// When array size exceeds the threshold, don't expand it into a DNF
COptimizerConfig *poconf = COptCtxt::PoctxtFromTLS()->Poconf();
ULONG ulArrayExpansionThreshold = poconf->Phint()->UlArrayExpansionThreshold();
if (ulArity > ulArrayExpansionThreshold)
{
return NULL;
}
DrgPcnstr *pdrgpcnstr = GPOS_NEW(pmp) DrgPcnstr(pmp);
for (ULONG ul = 0; ul < ulArity; ul++)
{
CScalarConst *popScConst = CUtils::PScalarArrayConstChildAt(pexprArray,ul);
CConstraintInterval *pci = CConstraintInterval::PciIntervalFromColConstCmp(pmp, pcr, ecmpt, popScConst);
pdrgpcnstr->Append(pci);
}
if (earrccmpt == CScalarArrayCmp::EarrcmpAny)
{
// predicate is of the form 'A IN (1,2,3)'
// return a disjunction of ranges {[1,1], [2,2], [3,3]}
return GPOS_NEW(pmp) CConstraintDisjunction(pmp, pdrgpcnstr);
}
// predicate is of the form 'A NOT IN (1,2,3)'
// return a conjunctive negation on {[1,1], [2,2], [3,3]}
return GPOS_NEW(pmp) CConstraintConjunction(pmp, pdrgpcnstr);
}
return NULL;
}
//---------------------------------------------------------------------------
// @function:
// CStatsPredUtils::ProcessArrayCmp
//
// @doc:
// Extract statistics filtering information from scalar array comparison
//---------------------------------------------------------------------------
void
CStatsPredUtils::ProcessArrayCmp
(
IMemoryPool *pmp,
CExpression *pexprPred,
DrgPstatspred *pdrgpstatspred
)
{
GPOS_ASSERT(NULL != pdrgpstatspred);
GPOS_ASSERT(NULL != pexprPred);
GPOS_ASSERT(2 == pexprPred->UlArity());
CScalarArrayCmp *popScArrayCmp = CScalarArrayCmp::PopConvert(pexprPred->Pop());
CExpression *pexprLeft = (*pexprPred)[0];
CExpression *pexprRight = (*pexprPred)[1];
BOOL fCompareToConst = ((COperator::EopScalarIdent == pexprLeft->Pop()->Eopid())
&& (COperator::EopScalarArray == pexprRight->Pop()->Eopid()));
if (!fCompareToConst)
{
// unsupported predicate for stats calculations
pdrgpstatspred->Append(GPOS_NEW(pmp) CStatsPredUnsupported(ULONG_MAX, CStatsPred::EstatscmptOther));
return;
}
BOOL fAny = (CScalarArrayCmp::EarrcmpAny == popScArrayCmp->Earrcmpt());
DrgPstatspred *pdrgpstatspredChild = pdrgpstatspred;
if (fAny)
{
pdrgpstatspredChild = GPOS_NEW(pmp) DrgPstatspred(pmp);
}
const ULONG ulConstants = pexprRight->UlArity();
// comparison semantics for statistics purposes is looser than regular comparison.
CStatsPred::EStatsCmpType escmpt = Estatscmptype(popScArrayCmp->PmdidOp());
CScalarIdent *popScalarIdent = CScalarIdent::PopConvert(pexprLeft->Pop());
const CColRef *pcr = popScalarIdent->Pcr();
if (!CHistogram::FSupportsFilter(escmpt))
{
// unsupported predicate for stats calculations
pdrgpstatspred->Append(GPOS_NEW(pmp) CStatsPredUnsupported(pcr->UlId(), escmpt));
return;
}
for (ULONG ul = 0; ul < ulConstants; ul++)
{
CExpression *pexprConst = (*pexprRight)[ul];
if (COperator::EopScalarConst == pexprConst->Pop()->Eopid())
{
CScalarConst *popScalarConst = CScalarConst::PopConvert(pexprConst->Pop());
IDatum *pdatumLiteral = popScalarConst->Pdatum();
CStatsPred *pstatspredChild = NULL;
if (!pdatumLiteral->FStatsComparable(pdatumLiteral))
{
// stats calculations on such datums unsupported
pstatspredChild = GPOS_NEW(pmp) CStatsPredUnsupported(pcr->UlId(), escmpt);
}
else
{
pstatspredChild = GPOS_NEW(pmp) CStatsPredPoint(pmp, pcr, escmpt, pdatumLiteral);
}
pdrgpstatspredChild->Append(pstatspredChild);
}
}
if (fAny)
{
CStatsPredDisj *pstatspredOr = GPOS_NEW(pmp) CStatsPredDisj(pdrgpstatspredChild);
pdrgpstatspred->Append(pstatspredOr);
}
}
//---------------------------------------------------------------------------
// @function:
// CPhysicalSequenceProject::CreateOrderSpec
//
// @doc:
// Create local order spec that we request relational child to satisfy
//
//---------------------------------------------------------------------------
void
CPhysicalSequenceProject::CreateOrderSpec
(
IMemoryPool *pmp
)
{
GPOS_ASSERT(NULL == m_pos);
GPOS_ASSERT(NULL != m_pds);
GPOS_ASSERT(NULL != m_pdrgpos);
m_pos = GPOS_NEW(pmp) COrderSpec(pmp);
// add partition by keys to order spec
if (CDistributionSpec::EdtHashed == m_pds->Edt())
{
CDistributionSpecHashed *pdshashed = CDistributionSpecHashed::PdsConvert(m_pds);
const DrgPexpr *pdrgpexpr = pdshashed->Pdrgpexpr();
const ULONG ulSize = pdrgpexpr->UlLength();
for (ULONG ul = 0; ul < ulSize; ul++)
{
CExpression *pexpr = (*pdrgpexpr)[ul];
// we assume partition-by keys are always scalar idents
CScalarIdent *popScId = CScalarIdent::PopConvert(pexpr->Pop());
const CColRef *pcr = popScId->Pcr();
gpmd::IMDId *pmdid = pcr->Pmdtype()->PmdidCmp(IMDType::EcmptL);
pmdid->AddRef();
m_pos->Append(pmdid, pcr, COrderSpec::EntLast);
}
}
if (0 == m_pdrgpos->UlLength())
{
return;
}
COrderSpec *posFirst = (*m_pdrgpos)[0];
#ifdef GPOS_DEBUG
const ULONG ulLength = m_pdrgpos->UlLength();
for (ULONG ul = 1; ul < ulLength; ul++)
{
COrderSpec *posCurrent = (*m_pdrgpos)[ul];
GPOS_ASSERT(posFirst->FSatisfies(posCurrent) &&
"first order spec must satisfy all other order specs");
}
#endif // GPOS_DEBUG
// we assume here that the first order spec in the children array satisfies all other
// order specs in the array, this happens as part of the initial normalization
// so we need to add columns only from the first order spec
const ULONG ulSize = posFirst->UlSortColumns();
for (ULONG ul = 0; ul < ulSize; ul++)
{
const CColRef *pcr = posFirst->Pcr(ul);
gpmd::IMDId *pmdid = posFirst->PmdidSortOp(ul);
pmdid->AddRef();
COrderSpec::ENullTreatment ent = posFirst->Ent(ul);
m_pos->Append(pmdid, pcr, ent);
}
}
