text: //---------------------------------------------------------------------------
  //	Greenplum Database
  //	Copyright (C) 2012 EMC Corp.
  //
  //	@filename:
  //		IMDRelStats.h
  //
  //	@doc:
  //		Interface for relation stats
  //---------------------------------------------------------------------------
  
  
  
  #ifndef GPMD_IMDRelStats_H
  #define GPMD_IMDRelStats_H
  
  #include "gpos/base.h"
  #include "gpos/common/CDouble.h"
  
  #include "naucrates/md/IMDCacheObject.h"
  
  namespace gpmd
  {
  using namespace gpos;
  using namespace gpdxl;
  
  //---------------------------------------------------------------------------
  //	@class:
  //		IMDRelStats
  //
  //	@doc:
  //		Interface for relation stats
  //
  //---------------------------------------------------------------------------
  class IMDRelStats : public IMDCacheObject
  {
  public:
  	// object type
  	virtual Emdtype
  	MDType() const
  	{
  		return EmdtRelStats;
  	}
  
  	// number of rows
  	virtual CDouble Rows() const = 0;
  
  	// is statistics on an empty input
  	virtual BOOL IsEmpty() const = 0;
  };
  }  // namespace gpmd
  
  #endif	// !GPMD_IMDRelStats_H
  
  // EOF
  