C++ (Cpp) CDrvdPropRelational::PcrsCorrelatedApply 예제들

예제 #1

파일: CLogical.cpp 프로젝트: HanumathRao/gporca

//---------------------------------------------------------------------------
//	@function:
//		CLogical::PcrsDeriveCorrelatedApply
//
//	@doc:
//		Derive columns from the inner child of a correlated-apply expression
//		that can be used above the apply expression
//
//---------------------------------------------------------------------------
CColRefSet *
CLogical::PcrsDeriveCorrelatedApply
	(
	IMemoryPool *pmp,
	CExpressionHandle &exprhdl
	)
	const
{
	GPOS_ASSERT(this == exprhdl.Pop());

	ULONG ulArity = exprhdl.UlArity();
	CColRefSet *pcrs = GPOS_NEW(pmp) CColRefSet(pmp);

	if (CUtils::FCorrelatedApply(exprhdl.Pop()))
	{
		// add inner columns of correlated-apply expression
		pcrs->Include(CLogicalApply::PopConvert(exprhdl.Pop())->PdrgPcrInner());
	}

	// combine correlated-apply columns from logical children
	for (ULONG ul = 0; ul < ulArity; ul++)
	{
		if (!exprhdl.FScalarChild(ul))
		{
			CDrvdPropRelational *pdprel = exprhdl.Pdprel(ul);
			pcrs->Union(pdprel->PcrsCorrelatedApply());
		}
	}

	return pcrs;
}