Re: EXPLAIN PLAN (Quite long posting)

Norman Dunbar wrote:
>
> Morning all, or therabouts,
>
> I'm wanting to educate my developers (and more importantly, myself) on
> the wierd and wonderful world of EXPLAIN PLAN.
>
> I've got the manual open, and have studied it, and I can actually make
> quite a lot of sense out of it myself, but I'd like to get deeper into
> it and fully (?) understand what it tells me, how to best read it etc.
> Does anyone have any good links, to info, tutorials, books, etc which
> cover it in more detail. The manual (817) gives about 20 pages - but
> most of that is simply a brief explanation of each of the possible
> plan_table columns.
>
> Oracle Performance Tuning 101 - covers it in about 3 pages, one simple
> example that even I can understand and not much more than that.
> Tom Kyte's Expert one-on-one Oracle - mentions it briefly in passing.
>
> Regards,
> Norman.
>
> ------------------------------------------------------------------------
> -----
> Norman Dunbar EMail: Norman.Dunbar_at_LFS.co.uk
> Database/Unix administrator Phone: 0113 289 6265
> Fax: 0113 289 3146
> Lynx Financial Systems Ltd. URL: http://www.Lynx-FS.com
> ------------------------------------------------------------------------
> -----

I would say the "Intro to the Optimzer" section is the 9i doc (Performance Guide). It talks about each of access paths the CBO can use. Then build a query to show an example of each and what would appear in the plan_table.

hth
connor

-- 
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Connor McDonald

http://www.oracledba.co.uk

"Some days you're the pigeon, some days you're the statue..."