greenplumn CLogicalAssert 代码
文件路径：/src/backend/gporca/libgpopt/src/operators/CLogicalAssert.cpp
/---------------------------------------------------------------------------
/ Greenplum Database
/ Copyright (C) 2012 EMC Corp.
/
/ @filename:
/ CLogicalAssert.cpp
/
/ @doc:
/ Implementation of assert operator
/---------------------------------------------------------------------------
#include "gpopt/operators/CLogicalAssert.h"
#include "gpos/base.h"
#include "gpopt/base/CColRefSet.h"
#include "gpopt/base/CColRefSetIter.h"
#include "gpopt/operators/CExpression.h"
#include "gpopt/operators/CExpressionHandle.h"
#include "gpopt/operators/CPatternTree.h"
#include "gpopt/operators/CPredicateUtils.h"
#include "naucrates/statistics/CStatisticsUtils.h"
using namespace gpopt;
/---------------------------------------------------------------------------
/ @function:
/ CLogicalAssert::CLogicalAssert
/
/ @doc:
/ Ctor - for pattern
/
/---------------------------------------------------------------------------
CLogicalAssert::CLogicalAssert(CMemoryPool *mp)
: CLogicalUnary(mp), m_pexc(nullptr)
{
m_fPattern = true;
}
/---------------------------------------------------------------------------
/ @function:
/ CLogicalAssert::CLogicalAssert
/
/ @doc:
/ Ctor
/
/---------------------------------------------------------------------------
CLogicalAssert::CLogicalAssert(CMemoryPool *mp, CException *pexc)
: CLogicalUnary(mp), m_pexc(pexc)
{
GPOS_ASSERT(nullptr != pexc);
}
/---------------------------------------------------------------------------
/ @function:
/ CLogicalAssert::Matches
/
/ @doc:
/ Match operators
/
/---------------------------------------------------------------------------
BOOL
CLogicalAssert::Matches(COperator *pop) const
{
if (Eopid() != pop->Eopid())
{
return false;
}
CLogicalAssert *popAssert = CLogicalAssert::PopConvert(pop);
return CException::Equals(*(popAssert->Pexc()), *m_pexc);
}
/---------------------------------------------------------------------------
/ @function:
/ CLogicalAssert::DeriveOutputColumns
/
/ @doc:
/ Derive output columns
/
/---------------------------------------------------------------------------
CColRefSet *
CLogicalAssert::DeriveOutputColumns(CMemoryPool *, / mp
CExpressionHandle &exprhdl)
{
return PcrsDeriveOutputPassThru(exprhdl);
}
/---------------------------------------------------------------------------
/ @function:
/ CLogicalAssert::PkcDeriveKeys
/
/ @doc:
/ Derive key collection
/
/---------------------------------------------------------------------------
CKeyCollection *
CLogicalAssert::DeriveKeyCollection(CMemoryPool *, / mp
CExpressionHandle &exprhdl) const
{
return PkcDeriveKeysPassThru(exprhdl, 0 /* ulChild */);
}
/---------------------------------------------------------------------------
/ @function:
/ CLogicalAssert::PxfsCandidates
/
/ @doc:
/ Get candidate xforms
/
/---------------------------------------------------------------------------
CXformSet *
CLogicalAssert::PxfsCandidates(CMemoryPool *mp) const
{
CXformSet *xform_set = GPOS_NEW(mp) CXformSet(mp);
(void) xform_set->ExchangeSet(CXform::ExfImplementAssert);
return xform_set;
}
/---------------------------------------------------------------------------
/ @function:
/ CLogicalAssert::DeriveMaxCard
/
/ @doc:
/ Derive max card
/
/---------------------------------------------------------------------------
CMaxCard
CLogicalAssert::DeriveMaxCard(CMemoryPool *, / mp
CExpressionHandle &exprhdl) const
{
/ in case of a false condition or a contradiction, maxcard should be 1
CExpression *pexprScalar = exprhdl.PexprScalarExactChild(1);
if ((nullptr != pexprScalar && CUtils::FScalarConstFalse(pexprScalar)) ||
exprhdl.DerivePropertyConstraint()->FContradiction())
{
return CMaxCard(1 /*ull*/);
}
/ if Assert operator was generated from MaxOneRow operator,
/ then a max cardinality of 1 is expected
if (nullptr != exprhdl.Pgexpr() &&
CXform::ExfMaxOneRow2Assert == exprhdl.Pgexpr()->ExfidOrigin())
{
return CMaxCard(1 /*ull*/);
}
/ pass on max card of first child
return exprhdl.DeriveMaxCard(0);
}
/---------------------------------------------------------------------------
/ @function:
/ CLogicalAssert::PstatsDerive
/
/ @doc:
/ Derive statistics based on filter predicates
/
/---------------------------------------------------------------------------
IStatistics *
CLogicalAssert::PstatsDerive(CMemoryPool *mp, CExpressionHandle &exprhdl,
IStatisticsArray * / not used
) const
{
CMaxCard maxcard =
CLogicalAssert::PopConvert(exprhdl.Pop())->DeriveMaxCard(mp, exprhdl);
if (1 == maxcard.Ull())
{
/ a max card of one requires re-scaling stats
IStatistics *stats = exprhdl.Pstats(0);
return stats->ScaleStats(mp, CDouble(1.0 / stats->Rows()));
}
return PstatsPassThruOuter(exprhdl);
}
/---------------------------------------------------------------------------
/ @function:
/ CLogicalAssert::OsPrint
/
/ @doc:
/ Debug print
/
/---------------------------------------------------------------------------
IOstream &
CLogicalAssert::OsPrint(IOstream &os) const
{
if (m_fPattern)
{
return COperator::OsPrint(os);
}
os << SzId() << " (Error code: " << m_pexc->GetSQLState() << ")";
return os;
}
/ EOF
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