Re: LIMIT Optimization - Mailing list pgsql-sql

From Bruce Momjian
Subject Re: LIMIT Optimization
Date
Msg-id 200201251936.g0PJaUQ10608@candle.pha.pa.us
Whole thread Raw
In response to Re: LIMIT Optimization  (Oleg Bartunov <oleg@sai.msu.su>)
Responses Re: LIMIT Optimization
List pgsql-sql
> if I'm not mistaken, it's called partial sorting, when you stop
> sorting process after getting desired number of rows specified by LIMIT clause.
> it's extremely friendly for web applications, because 90% of users
> just read the first page of results. We already discussed this feature
> sometime during 7.1 dev and even made very crude patch. In our tests we
> got performance win of factor 5-6 ( getting first 100 row from 1mln ).
> We hope sometime we'll return to this.

But we already have cursor's assuming 10% return.  Is allowing that
value to be changed using SET an acceptable solution?

--  Bruce Momjian                        |  http://candle.pha.pa.us pgman@candle.pha.pa.us               |  (610)
853-3000+  If your life is a hard drive,     |  830 Blythe Avenue +  Christ can be your backup.        |  Drexel Hill,
Pennsylvania19026
 


pgsql-sql by date:

Previous
From: Tom Lane
Date:
Subject: Re: Good tutorial on plperl.
Next
From: Oleg Bartunov
Date:
Subject: Re: LIMIT Optimization