Re: GIN index creation extremely slow ?

From: Teodor Sigaev <teodor(at)sigaev(dot)ru>
To: Stefan Kaltenbrunner <stefan(at)kaltenbrunner(dot)cc>
Cc: PostgreSQL-development <pgsql-hackers(at)postgresql(dot)org>
Subject: Re: GIN index creation extremely slow ?
Date: 2006-07-11 19:59:30
Message-ID: 44B40322.60704@sigaev.ru
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-hackers

Try again, today's patch solves the problem.

Stefan Kaltenbrunner wrote:
> on IRC somebody mentioned that it took >34h to greate a GIN index (on a
> tsvector) on a ~3 Million column table (wikipedia dump) with a
> reasonable speced box (AMD 3400+).
> After getting hold of a dump of said table (around 4,1GB in size) I
> managed to get the following timings:
>
> test=# CREATE INDEX idxFTI_idx ON wikipedia USING gist(vector);
> CREATE INDEX
> Time: 416122.896 ms
>
> so about 7 minutes - sounds very reasonable
>
> test=# CREATE INDEX idxFTI2_idx ON wikipedia USING gin(vector);
> CREATE INDEX
> Time: 52681605.101 ms
>
> ouch - that makes for a whoppy 14,6hours(!). During that time the box is
> completely CPU bottlenecked and during virtually no IO at all - (varing
> maintainance_work_mem does not seem to make any noticable difference).
>
> That box is a fast Dual Opteron 2.6Ghz with 8GB RAM and a 4 disk RAID10
> for the WAL and 12 disks for the data running a very recent -HEAD
> checkout ...
>
> It looks like we still don't have any docs for GIN in the tree so I
> don't know if those timings are expected or not ...
>
>
> Stefan
>
> ---------------------------(end of broadcast)---------------------------
> TIP 2: Don't 'kill -9' the postmaster

--
Teodor Sigaev E-mail: teodor(at)sigaev(dot)ru
WWW: http://www.sigaev.ru/

In response to

Browse pgsql-hackers by date

  From Date Subject
Next Message Greg Stark 2006-07-11 20:04:10 Re: pgsql-patches considered harmful
Previous Message Marko Kreen 2006-07-11 19:57:42 [patch 9/9] Include code for bignum math