greenplumn CDXLColStats 代码
文件路径：/src/backend/gporca/libnaucrates/include/naucrates/md/CDXLColStats.h
/---------------------------------------------------------------------------
/ Greenplum Database
/ Copyright (C) 2012 EMC Corp.
/
/ @filename:
/ CDXLColStats.h
/
/ @doc:
/ Class representing column stats
/---------------------------------------------------------------------------
#ifndef GPMD_CDXLColStats_H
#define GPMD_CDXLColStats_H
#include "gpos/base.h"
#include "gpos/common/CDouble.h"
#include "gpos/common/CDynamicPtrArray.h"
#include "gpos/string/CWStringDynamic.h"
#include "naucrates/md/CDXLBucket.h"
#include "naucrates/md/CMDIdColStats.h"
#include "naucrates/md/IMDColStats.h"
namespace gpdxl
{
class CXMLSerializer;
}
namespace gpmd
{
using namespace gpos;
using namespace gpdxl;
/---------------------------------------------------------------------------
/ @class:
/ CDXLColStats
/
/ @doc:
/ Class representing column stats
/
/---------------------------------------------------------------------------
class CDXLColStats : public IMDColStats
{
private:
/ memory pool
CMemoryPool *m_mp;
/ metadata id of the object
CMDIdColStats *m_mdid_col_stats;
/ column name
CMDName *m_mdname;
/ column width
CDouble m_width;
/ null fraction
CDouble m_null_freq;
/ ndistinct of remaining tuples
CDouble m_distinct_remaining;
/ frequency of remaining tuples
CDouble m_freq_remaining;
/ histogram buckets
CDXLBucketArray *m_dxl_stats_bucket_array;
/ is column statistics missing in the database
BOOL m_is_col_stats_missing;
/ DXL string for object
CWStringDynamic *m_dxl_str;
public:
CDXLColStats(const CDXLColStats &) = delete;
/ ctor
CDXLColStats(CMemoryPool *mp, CMDIdColStats *mdid_col_stats,
CMDName *mdname, CDouble width, CDouble null_freq,
CDouble distinct_remaining, CDouble freq_remaining,
CDXLBucketArray *dxl_stats_bucket_array,
BOOL is_col_stats_missing);
/ dtor
~CDXLColStats() override;
/ the metadata id
IMDId *MDId() const override;
/ relation name
CMDName Mdname() const override;
/ DXL string representation of cache object
const CWStringDynamic *GetStrRepr() const override;
/ number of buckets
ULONG Buckets() const override;
/ width
CDouble
Width() const override
{
return m_width;
}
/ null fraction
CDouble
GetNullFreq() const override
{
return m_null_freq;
}
/ ndistinct of remaining tuples
CDouble
GetDistinctRemain() const override
{
return m_distinct_remaining;
}
/ frequency of remaining tuples
CDouble
GetFreqRemain() const override
{
return m_freq_remaining;
}
/ is the column statistics missing in the database
BOOL
IsColStatsMissing() const override
{
return m_is_col_stats_missing;
}
/ get the bucket at the given position
const CDXLBucket *GetDXLBucketAt(ULONG ul) const override;
/ serialize column stats in DXL format
void Serialize(gpdxl::CXMLSerializer *) const override;
#ifdef GPOS_DEBUG
/ debug print of the column stats
void DebugPrint(IOstream &os) const override;
#endif
/ dummy colstats
static CDXLColStats *CreateDXLDummyColStats(CMemoryPool *mp, IMDId *mdid,
CMDName *mdname, CDouble width);
};
/ array of dxl column stats
using CDXLColStatsArray = CDynamicPtrArray<CDXLColStats, CleanupRelease>;
} / namespace gpmd
#endif / !GPMD_CDXLColStats_H
/ EOF
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