//---------------------------------------------------------------------------
// @function:
// CNormalizer::PushThruSetOp
//
// @doc:
// Push a conjunct through set operation
//
//---------------------------------------------------------------------------
void
CNormalizer::PushThruSetOp
(
IMemoryPool *pmp,
CExpression *pexprSetOp,
CExpression *pexprConj,
CExpression **ppexprResult
)
{
GPOS_ASSERT(NULL != pexprSetOp);
GPOS_ASSERT(CUtils::FLogicalSetOp(pexprSetOp->Pop()));
GPOS_ASSERT(NULL != pexprConj);
GPOS_ASSERT(NULL != ppexprResult);
CLogicalSetOp *popSetOp = CLogicalSetOp::PopConvert(pexprSetOp->Pop());
DrgPcr *pdrgpcrOutput = popSetOp->PdrgpcrOutput();
CColRefSet *pcrsOutput = GPOS_NEW(pmp) CColRefSet(pmp, pdrgpcrOutput);
DrgDrgPcr *pdrgpdrgpcrInput = popSetOp->PdrgpdrgpcrInput();
DrgPexpr *pdrgpexprNewChildren = GPOS_NEW(pmp) DrgPexpr(pmp);
const ULONG ulArity = pexprSetOp->UlArity();
for (ULONG ul = 0; ul < ulArity; ul++)
{
CExpression *pexprChild = (*pexprSetOp)[ul];
DrgPcr *pdrgpcrChild = (*pdrgpdrgpcrInput)[ul];
CColRefSet *pcrsChild = GPOS_NEW(pmp) CColRefSet(pmp, pdrgpcrChild);
pexprConj->AddRef();
CExpression *pexprRemappedConj = pexprConj;
if (!pcrsChild->FEqual(pcrsOutput))
{
// child columns are different from SetOp output columns,
// we need to fix conjunct by mapping output columns to child columns,
// columns that are not in the output of SetOp child need also to be re-mapped
// to new columns,
//
// for example, if the conjunct looks like 'x > (select max(y) from T)'
// and the SetOp child produces only column x, we need to create a new
// conjunct that looks like 'x1 > (select max(y1) from T)'
// where x1 is a copy of x, and y1 is a copy of y
//
// this is achieved by passing (fMustExist = True) flag below, which enforces
// creating column copies for columns not already in the given map
HMUlCr *phmulcr = CUtils::PhmulcrMapping(pmp, pdrgpcrOutput, pdrgpcrChild);
pexprRemappedConj->Release();
pexprRemappedConj = pexprConj->PexprCopyWithRemappedColumns(pmp, phmulcr, true /*fMustExist*/);
phmulcr->Release();
}
CExpression *pexprNewChild = NULL;
PushThru(pmp, pexprChild, pexprRemappedConj, &pexprNewChild);
pdrgpexprNewChildren->Append(pexprNewChild);
pexprRemappedConj->Release();
pcrsChild->Release();
}
pcrsOutput->Release();
popSetOp->AddRef();
*ppexprResult = GPOS_NEW(pmp) CExpression(pmp, popSetOp, pdrgpexprNewChildren);
}
//---------------------------------------------------------------------------
// @function:
// CLogicalSetOp::FMatch
//
// @doc:
// Match function on operator level
//
//---------------------------------------------------------------------------
BOOL
CLogicalSetOp::FMatch
(
COperator *pop
)
const
{
if (pop->Eopid() != Eopid())
{
return false;
}
CLogicalSetOp *popSetOp = CLogicalSetOp::PopConvert(pop);
DrgDrgPcr *pdrgpdrgpcrInput = popSetOp->PdrgpdrgpcrInput();
const ULONG ulArity = pdrgpdrgpcrInput->UlLength();
if (ulArity != m_pdrgpdrgpcrInput->UlLength() ||
!m_pdrgpcrOutput->FEqual(popSetOp->PdrgpcrOutput()))
{
return false;
}
for (ULONG ul = 0; ul < ulArity; ul++)
{
if (!(*m_pdrgpdrgpcrInput)[ul]->FEqual((*pdrgpdrgpcrInput)[ul]))
{
return false;
}
}
return true;
}
