If  RTS (real time statistics)  is enabled then DB2 will collect the statistics internally. If no  RTS is used then it  will use whatever statistics  were present  from before  when a  statistics  was collected last. If the  table never had  statistics  then it  requests the storage layer to tell  the physical size of the table. Then  it will use the physical size, coupled with the UDI  (Update Delete Insert) counter, to fabricate statistics. A  fabrication... [More]

Tags:  statistics db2 runstats initial fabrication udi