Re: Mnogosearch (Was: Re: website doc search is ... )
Tom Lane <tgl@sss.pgh.pa.us>
From: Tom Lane <tgl@sss.pgh.pa.us>
To: "Marc G. Fournier" <scrappy@postgresql.org>
Cc: Mark Kirkwood <markir@paradise.net.nz>, Bruce Momjian <pgman@candle.pha.pa.us>, "pgsql-general@postgresql.org" <pgsql-general@postgresql.org>
Date: 2004-01-01T19:17:50Z
Lists: pgsql-general
"Marc G. Fournier" <scrappy@postgresql.org> writes: > I don't see a difference between the two, other then time changes, but > that could just be that runA had a server a bit more idle then runB ... > something I'm not seeing here? Well, the difference I was hoping for was a more accurate rows estimate for the indexscan, which indeed we got (estimate went from 3210 to 16075, vs reality of 15533). But it didn't change the plan :-(. Looking more closely, I see the rows estimate for the seqscan on "url" is pretty awful too (1968 vs reality of 304811). I think it would get better if you were doing just AND (url.url LIKE 'http://archives.postgresql.org/%%'); without the concatenation of an empty string. Is there a reason for the concatenation part of the expression? regards, tom lane