//---------------------------------------------------------------------------
// @function:
// CColumnFactory::PcrCopy
//
// @doc:
// Create a copy of the given colref
//
//---------------------------------------------------------------------------
CColRef *
CColumnFactory::PcrCopy
(
const CColRef* colref
)
{
CName name(colref->Name());
if (CColRef::EcrtComputed == colref->Ecrt())
{
return PcrCreate(colref->RetrieveType(), colref->TypeModifier(), name);
}
GPOS_ASSERT(CColRef::EcrtTable == colref->Ecrt());
ULONG id = m_aul.Incr();
CColRefTable *pcrTable = CColRefTable::PcrConvert(const_cast<CColRef*>(colref));
return PcrCreate
(
colref->RetrieveType(),
colref->TypeModifier(),
pcrTable->AttrNum(),
pcrTable->IsNullable(),
id,
name,
pcrTable->UlSourceOpId(),
pcrTable->Width()
);
}
//---------------------------------------------------------------------------
// @function:
// CLogicalGet::PcrsDeriveNotNull
//
// @doc:
// Derive not null output columns
//
//---------------------------------------------------------------------------
CColRefSet *
CLogicalGet::PcrsDeriveNotNull
(
IMemoryPool *mp,
CExpressionHandle &exprhdl
)
const
{
// get all output columns
CColRefSet *pcrs = GPOS_NEW(mp) CColRefSet(mp);
pcrs->Include(CDrvdPropRelational::GetRelationalProperties(exprhdl.Pdp())->PcrsOutput());
// filters out nullable columns
CColRefSetIter crsi(*CDrvdPropRelational::GetRelationalProperties(exprhdl.Pdp())->PcrsOutput());
while (crsi.Advance())
{
CColRefTable *pcrtable = CColRefTable::PcrConvert(const_cast<CColRef*>(crsi.Pcr()));
if (pcrtable->IsNullable())
{
pcrs->Exclude(pcrtable);
}
}
return pcrs;
}