Explain Plan

[Quoted] Hi All,

Ok, so now that I've turned on tracing, generated a trace file, ran TKPROF and have some output, how the heck an I supposed to interpt this:

I mean, in plain english, how can I look at my query and know what exactly happened. I just do not know how to read these.....

I have to do these a lot, so I need to know if there is a method to understanding all this stuff:

Rows Row Source Operation

-------  ---------------------------------------------------
     14  MERGE JOIN OUTER
     15   VIEW
     15    SORT GROUP BY
     14     NESTED LOOPS
     15      NESTED LOOPS
     15       NESTED LOOPS
     15        FIXED TABLE FULL X$KCCFE
     28        FIXED TABLE FIXED INDEX #1 X$KCCFN
     28       FIXED TABLE FULL X$KCCTS
     14      FIXED TABLE FIXED INDEX #1 X$KCVFH
      9   SORT JOIN
      9    VIEW
      9     SORT GROUP BY
      9      VIEW DBA_FREE_SPACE
      9       UNION-ALL
      1        NESTED LOOPS
      2         NESTED LOOPS
     15          INDEX FAST FULL SCAN (object id 39)
     15          TABLE ACCESS CLUSTER FET$
     28           INDEX UNIQUE SCAN (object id 7)
      1         TABLE ACCESS CLUSTER TS$
      8        NESTED LOOPS
      9         NESTED LOOPS
     14          TABLE ACCESS FULL TS$
     21          FIXED TABLE FIXED INDEX #1 X$KTFBFE
      8         INDEX UNIQUE SCAN (object id 39)

Thanks,

Arthur Received on Thu Feb 03 2005 - 23:08:06 CET