Expert Oracle Exadata - Parent Directory

CHAPTER 6 MAKING PCBSNow we’ll show some statistics before and after executing the statement. You’ll be able to see thatwhile the physical reads statistic does not increase, the logical reads statistic shows a large increase. Notethat we’ve done a quick calculation of the total number of logical reads by selecting from dual, and thatthe number of logical reads (162,715) is very close to the number of blocks that the table occupies asreported by DBA_TABLES.SYS@EXDB1> @flush_poolSystem altered.SYS@EXDB1> @mystatsEnter value for name: readsNAMEVALUE---------------------------------------------------------------- ----------cold recycle reads 0data blocks consistent reads - undo records applied 0lob reads 0physical reads 4706178physical reads cache 30physical reads cache prefetch 0physical reads direct 4706148physical reads direct (lob) 0physical reads direct temporary tablespace 0physical reads for flashback new 0physical reads prefetch warmup 0physical reads retry corrupt 0recovery array reads 0session logical reads 7152779transaction tables consistent reads - undo records applied 015 rows selected.SYS@EXDB1> set timing onSYS@EXDB1> @avgskewAVG(PK_COL)-----------16093750.81 row selected.Elapsed: 00:00:00.72SYS@EXDB1> set timing offSYS@EXDB1> @mystatsEnter value for name: readsNAMEVALUE-------------------------------------------------------------- ------------cold recycle reads 0data blocks consistent reads - undo records applied 0lob reads 0168