//---------------------------------------------------------------------------
// @function:
// CLogical::PpcDeriveConstraintRestrict
//
// @doc:
// Derive constraint property only on the given columns
//
//---------------------------------------------------------------------------
CPropConstraint *
CLogical::PpcDeriveConstraintRestrict
(
IMemoryPool *pmp,
CExpressionHandle &exprhdl,
CColRefSet *pcrsOutput
)
{
// constraint property from relational child
CPropConstraint *ppc = exprhdl.Pdprel(0)->Ppc();
DrgPcrs *pdrgpcrs = ppc->PdrgpcrsEquivClasses();
// construct new array of equivalence classes
DrgPcrs *pdrgpcrsNew = GPOS_NEW(pmp) DrgPcrs(pmp);
const ULONG ulLen = pdrgpcrs->UlLength();
for (ULONG ul = 0; ul < ulLen; ul++)
{
CColRefSet *pcrsEquiv = GPOS_NEW(pmp) CColRefSet(pmp);
pcrsEquiv->Include((*pdrgpcrs)[ul]);
pcrsEquiv->Intersection(pcrsOutput);
if (0 < pcrsEquiv->CElements())
{
pdrgpcrsNew->Append(pcrsEquiv);
}
else
{
pcrsEquiv->Release();
}
}
CConstraint *pcnstrChild = ppc->Pcnstr();
if (NULL == pcnstrChild)
{
return GPOS_NEW(pmp) CPropConstraint(pmp, pdrgpcrsNew, NULL);
}
DrgPcnstr *pdrgpcnstr = GPOS_NEW(pmp) DrgPcnstr(pmp);
// include only constraints on given columns
CColRefSetIter crsi(*pcrsOutput);
while (crsi.FAdvance())
{
CColRef *pcr = crsi.Pcr();
CConstraint *pcnstrCol = pcnstrChild->Pcnstr(pmp, pcr);
if (NULL == pcnstrCol)
{
continue;
}
if (pcnstrCol->FUnbounded())
{
pcnstrCol->Release();
continue;
}
pdrgpcnstr->Append(pcnstrCol);
}
CConstraint *pcnstr = CConstraint::PcnstrConjunction(pmp, pdrgpcnstr);
return GPOS_NEW(pmp) CPropConstraint(pmp, pdrgpcrsNew, pcnstr);
}
//---------------------------------------------------------------------------
// @function:
// CConstraint::PcnstrFromScalarBoolOp
//
// @doc:
// Create constraint from scalar boolean expression
//
//---------------------------------------------------------------------------
CConstraint *
CConstraint::PcnstrFromScalarBoolOp
(
IMemoryPool *pmp,
CExpression *pexpr,
DrgPcrs **ppdrgpcrs // output equivalence classes
)
{
GPOS_ASSERT(NULL != pexpr);
GPOS_ASSERT(CUtils::FScalarBoolOp(pexpr));
GPOS_ASSERT(NULL != ppdrgpcrs);
GPOS_ASSERT(NULL == *ppdrgpcrs);
*ppdrgpcrs = GPOS_NEW(pmp) DrgPcrs(pmp);
DrgPcnstr *pdrgpcnstr = GPOS_NEW(pmp) DrgPcnstr(pmp);
const ULONG ulArity= pexpr->UlArity();
for (ULONG ul = 0; ul < ulArity; ul++)
{
DrgPcrs *pdrgpcrsChild = NULL;
CConstraint *pcnstrChild = PcnstrFromScalarExpr(pmp, (*pexpr)[ul], &pdrgpcrsChild);
if (NULL == pcnstrChild || pcnstrChild->FUnbounded())
{
CRefCount::SafeRelease(pcnstrChild);
CRefCount::SafeRelease(pdrgpcrsChild);
if (CPredicateUtils::FOr(pexpr))
{
pdrgpcnstr->Release();
return NULL;
}
continue;
}
GPOS_ASSERT(NULL != pdrgpcrsChild);
pdrgpcnstr->Append(pcnstrChild);
DrgPcrs *pdrgpcrsMerged = PdrgpcrsMergeFromBoolOp(pmp, pexpr, *ppdrgpcrs, pdrgpcrsChild);
(*ppdrgpcrs)->Release();
*ppdrgpcrs = pdrgpcrsMerged;
pdrgpcrsChild->Release();
}
const ULONG ulLen = pdrgpcnstr->UlLength();
if (0 == ulLen)
{
pdrgpcnstr->Release();
return NULL;
}
if (1 == ulLen)
{
CConstraint *pcnstrChild = (*pdrgpcnstr)[0];
pcnstrChild->AddRef();
pdrgpcnstr->Release();
if (CPredicateUtils::FNot(pexpr))
{
return GPOS_NEW(pmp) CConstraintNegation(pmp, pcnstrChild);
}
return pcnstrChild;
}
// we know we have more than one child
if (CPredicateUtils::FAnd(pexpr))
{
return GPOS_NEW(pmp) CConstraintConjunction(pmp, pdrgpcnstr);
}
if (CPredicateUtils::FOr(pexpr))
{
return GPOS_NEW(pmp) CConstraintDisjunction(pmp, pdrgpcnstr);
}
return NULL;
}
//---------------------------------------------------------------------------
// @function:
// CLogicalDynamicGetBase::PstatsDeriveFilter
//
// @doc:
// Derive stats from base table using filters on partition and/or index columns
//
//---------------------------------------------------------------------------
IStatistics *
CLogicalDynamicGetBase::PstatsDeriveFilter
(
IMemoryPool *pmp,
CExpressionHandle &exprhdl,
CExpression *pexprFilter
)
const
{
CExpression *pexprFilterNew = NULL;
CConstraint *pcnstr = m_ppartcnstr->PcnstrCombined();
if (m_fPartial && NULL != pcnstr && !pcnstr->FUnbounded())
{
if (NULL == pexprFilter)
{
pexprFilterNew = pcnstr->PexprScalar(pmp);
pexprFilterNew->AddRef();
}
else
{
pexprFilterNew = CPredicateUtils::PexprConjunction(pmp, pexprFilter, pcnstr->PexprScalar(pmp));
}
}
else if (NULL != pexprFilter)
{
pexprFilterNew = pexprFilter;
pexprFilterNew->AddRef();
}
CColRefSet *pcrsStat = GPOS_NEW(pmp) CColRefSet(pmp);
CDrvdPropScalar *pdpscalar = NULL;
if (NULL != pexprFilterNew)
{
pdpscalar = CDrvdPropScalar::Pdpscalar(pexprFilterNew->PdpDerive());
pcrsStat->Include(pdpscalar->PcrsUsed());
}
// requesting statistics on distribution columns to estimate data skew
if (NULL != m_pcrsDist)
{
pcrsStat->Include(m_pcrsDist);
}
IStatistics *pstatsFullTable = PstatsBaseTable(pmp, exprhdl, m_ptabdesc, pcrsStat);
pcrsStat->Release();
if (NULL == pexprFilterNew || pdpscalar->FHasSubquery())
{
return pstatsFullTable;
}
CStatsPred *pstatspred = CStatsPredUtils::PstatspredExtract
(
pmp,
pexprFilterNew,
NULL /*pcrsOuterRefs*/
);
pexprFilterNew->Release();
IStatistics *pstatsResult = pstatsFullTable->PstatsFilter
(
pmp,
pstatspred,
true /* fCapNdvs */
);
pstatspred->Release();
pstatsFullTable->Release();
return pstatsResult;
}
