Re: Explain Plan

amerar_at_iwc.net wrote:

> 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

First thing I interpret from your explain plan is that you are querying objects in the data dictionary. Show us your SQL and the version. As is this is meaningless.

-- 
Daniel A. Morgan
University of Washington
damorgan_at_x.washington.edu
(replace 'x' with 'u' to respond)