greenplumn CColRefTable 代码
文件路径：/src/backend/gporca/libgpopt/include/gpopt/base/CColRefTable.h
/---------------------------------------------------------------------------
/ Greenplum Database
/ Copyright (C) 2011 EMC Corp.
/
/ @filename:
/ CColRefTable.h
/
/ @doc:
/ Column reference implementation for base table columns
/---------------------------------------------------------------------------
#ifndef GPOS_CColRefTable_H
#define GPOS_CColRefTable_H
#include "gpos/base.h"
#include "gpos/common/CDynamicPtrArray.h"
#include "gpos/common/CList.h"
#include "gpopt/base/CColRef.h"
#include "gpopt/metadata/CColumnDescriptor.h"
#include "gpopt/metadata/CName.h"
namespace gpopt
{
using namespace gpos;
/---------------------------------------------------------------------------
/ @class:
/ CColRefTable
/
/ @doc:
/ Column reference for base table columns
/
/---------------------------------------------------------------------------
class CColRefTable : public CColRef
{
private:
/ attno from catalog
INT m_iAttno;
/ does column allow null values
BOOL m_is_nullable;
/ id of the operator which is the source of this column reference
/ not owned
ULONG m_ulSourceOpId;
/ is the column a distribution key
BOOL m_is_dist_col;
/ width of the column, for instance char(10) column has width 10
ULONG m_width;
public:
CColRefTable(const CColRefTable &) = delete;
/ ctors
CColRefTable(const CColumnDescriptor *pcd, ULONG id, const CName *pname,
ULONG ulOpSource);
CColRefTable(const IMDType *pmdtype, INT type_modifier, INT attno,
BOOL is_nullable, ULONG id, const CName *pname,
ULONG ulOpSource, BOOL is_dist_col,
ULONG ulWidth = gpos::ulong_max);
/ dtor
~CColRefTable() override;
/ accessor of column reference type
CColRef::Ecolreftype
Ecrt() const override
{
return CColRef::EcrtTable;
}
/ accessor of attribute number
INT
AttrNum() const
{
return m_iAttno;
}
/ does column allow null values?
BOOL
IsNullable() const
{
return m_is_nullable;
}
/ is column a system column?
BOOL
IsSystemCol() const override
{
/ TODO- 04/13/2012, make this check system independent
/ using MDAccessor
return 0 >= m_iAttno;
}
/ is column a distribution column?
BOOL
IsDistCol() const override
{
return m_is_dist_col;
}
/ width of the column
ULONG
Width() const
{
return m_width;
}
/ id of source operator
ULONG
UlSourceOpId() const
{
return m_ulSourceOpId;
}
/ conversion
static CColRefTable *
PcrConvert(CColRef *cr)
{
GPOS_ASSERT(cr->Ecrt() == CColRef::EcrtTable);
return dynamic_cast<CColRefTable *>(cr);
}
}; / class CColRefTable
} / namespace gpopt
#endif / !GPOS_CColRefTable_H
/ EOF
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