C++ (Cpp) CExpression::PexprCopyWithRemappedColumns示例

示例#1

文件： CDistributionSpecHashed.cpp 项目： whatcat/gporca

//---------------------------------------------------------------------------
//	@function:
//		CDistributionSpecHashed::PdsCopyWithRemappedColumns
//
//	@doc:
//		Return a copy of the distribution spec with remapped columns
//
//---------------------------------------------------------------------------
CDistributionSpec *
CDistributionSpecHashed::PdsCopyWithRemappedColumns
	(
	IMemoryPool *pmp,
	HMUlCr *phmulcr,
	BOOL fMustExist
	)
{
	DrgPexpr *pdrgpexpr = GPOS_NEW(pmp) DrgPexpr(pmp);
	const ULONG ulLen = m_pdrgpexpr->UlLength();
	for (ULONG ul = 0; ul < ulLen; ul++)
	{
		CExpression *pexpr = (*m_pdrgpexpr)[ul];
		pdrgpexpr->Append(pexpr->PexprCopyWithRemappedColumns(pmp, phmulcr, fMustExist));
	}

	if (NULL == m_pdshashedEquiv)
	{
		return GPOS_NEW(pmp) CDistributionSpecHashed(pdrgpexpr, m_fNullsColocated);
	}

	// copy equivalent distribution
	CDistributionSpec *pds = m_pdshashedEquiv->PdsCopyWithRemappedColumns(pmp, phmulcr, fMustExist);
	CDistributionSpecHashed *pdshashed = CDistributionSpecHashed::PdsConvert(pds);
	return GPOS_NEW(pmp) CDistributionSpecHashed(pdrgpexpr, m_fNullsColocated, pdshashed);
}