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Re: Please help tuning a query

From: Anurag Varma <avarmadba.skipthis_at_yahoo.com>
Date: Fri, 09 May 2003 04:41:12 GMT
Message-ID: <IjGua.1503$5Y1.1228@nwrdny01.gnilink.net>


:) I guess I misunderstood on the wrapping part.

Anyway .. good luck on your tuning. Just a suggestion you might want to try in test: Try generating
histograms for the columns (or indexed columns) of the tables being joined. Especially if the
application uses literals and if the data is skewed in those columns ... and if your query is using
a filter on those columns. Might help.
and/or up the estimate from 20 to a higher number if thats feasible for you.

Also, as per Sybrand's suggestion .. set those optimizer_* settings to something more appropriate.
However, test test test ... before implementing them in production. For example, very low setting on
optimizer_index_cost_adj might lead oracle into using index/nested loops a little too much.

Anurag

"Ryan Gaffuri" <rgaffuri_at_cox.net> wrote in message news:1efdad5b.0305080409.195c0f2a_at_posting.google.com... > "Anurag Varma" <avdbi_at_hotmail.com> wrote in message news:<cckua.4810$3x5.1985_at_news01.roc.ny.frontiernet.net>...
> > "Ryan" <rgaffuri_at_cox.net> wrote in message
news:lYeua.36572$g41.3165426_at_news1.east.cox.net...
> > > is there anyway to get that plan to line up so people can read it? Im
not
> > > using tabs. Just the space bar?
> > >
> > >
> >
> > set linesize 120
> > col plan_plus_exp format a99
> >
> > might help....
> >
> > Anurag

>
> I know how to do it in SQL*Plus its the board that messing it up.
> Noone is going to want to read a plan posted like that.
>
> I know the cursor select then update by rowid is faster. Its just
> building a bad plan. There are indices and it should not use a sort
> merge. Ill have to mess with it some more to figure out what is going
> on. Sort Merge = Death sentence for performance.
Received on Thu May 08 2003 - 23:41:12 CDT

Original text of this message

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