//---------------------------------------------------------------------------
// @function:
// CXformGbAgg2StreamAgg::Transform
//
// @doc:
// Actual transformation
//
//---------------------------------------------------------------------------
void
CXformGbAgg2StreamAgg::Transform
(
CXformContext *pxfctxt,
CXformResult *pxfres,
CExpression *pexpr
)
const
{
GPOS_ASSERT(NULL != pxfctxt);
GPOS_ASSERT(FPromising(pxfctxt->Pmp(), this, pexpr));
GPOS_ASSERT(FCheckPattern(pexpr));
CLogicalGbAgg *popAgg = CLogicalGbAgg::PopConvert(pexpr->Pop());
IMemoryPool *pmp = pxfctxt->Pmp();
DrgPcr *pdrgpcr = popAgg->Pdrgpcr();
pdrgpcr->AddRef();
// extract components
CExpression *pexprRel = (*pexpr)[0];
CExpression *pexprScalar = (*pexpr)[1];
// addref children
pexprRel->AddRef();
pexprScalar->AddRef();
DrgPcr *pdrgpcrArgDQA = popAgg->PdrgpcrArgDQA();
if (0 != pdrgpcrArgDQA->UlSafeLength())
{
GPOS_ASSERT(NULL != pdrgpcrArgDQA);
pdrgpcrArgDQA->AddRef();
}
// create alternative expression
CExpression *pexprAlt =
GPOS_NEW(pmp) CExpression
(
pmp,
GPOS_NEW(pmp) CPhysicalStreamAgg
(
pmp,
pdrgpcr,
popAgg->PdrgpcrMinimal(),
popAgg->Egbaggtype(),
popAgg->FGeneratesDuplicates(),
pdrgpcrArgDQA,
CXformUtils::FMultiStageAgg(pexpr)
),
pexprRel,
pexprScalar
);
// add alternative to transformation result
pxfres->Add(pexprAlt);
}
//---------------------------------------------------------------------------
// @function:
// CXformSimplifyGbAgg::Exfp
//
// @doc:
// Compute xform promise for a given expression handle;
// aggregate must have grouping columns
//
//---------------------------------------------------------------------------
CXform::EXformPromise
CXformSimplifyGbAgg::Exfp
(
CExpressionHandle &exprhdl
)
const
{
CLogicalGbAgg *popAgg = CLogicalGbAgg::PopConvert(exprhdl.Pop());
GPOS_ASSERT(COperator::EgbaggtypeGlobal == popAgg->Egbaggtype());
if (0 == popAgg->Pdrgpcr()->UlLength() || NULL != popAgg->PdrgpcrMinimal())
{
return CXform::ExfpNone;
}
return CXform::ExfpHigh;
}
