Re: Index creation takes for ever

Hi Tom,
This is on unixware 7 (both 7.3.4 and 7.4b)

I'm on the FR language (I'll re-initdb whith lang=C to see what happens)
But I never had a problem before.
Waiting for a reply, I drop the table after copying it, and arranged sql
script to create the indexes BEFORE the COPY

The overall process took only 5 Min.
On Thu, 28 Aug 2003, Tom Lane wrote:

> Date: Thu, 28 Aug 2003 10:13:21 -0400
> From: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
> To: ohp(at)pyrenet(dot)fr
> Cc: pgsql-hackers list <pgsql-hackers(at)postgresql(dot)org>
> Subject: Re: [HACKERS] Index creation takes for ever
>
> ohp(at)pyrenet(dot)fr writes:
> > I've then pg_dump'ed the database and recreate an other both on 7.3.4 and
> > 7.4b
>
> > Both are still running after more than 30 minutes of CPU (100% cpu taken)
> > creating the levt_lu_ligne_evt_key.
>
> That's hard to believe. I get
>
> regression=# SELECT levt_lu,count(*) from ligne_evt group by levt_lu;
> levt_lu | count
> ---------+--------
> N | 49435
> O | 181242
> (2 rows)
>
> Time: 6927.28 ms
> regression=# create index levt_lu_ligne_evt_key on ligne_evt (levt_lu);
> CREATE INDEX
> Time: 14946.74 ms
>
> on a not-very-fast machine ... and it seems to be mostly I/O bound.
>
> What platform are you on? I could believe that the local qsort() is
> incredibly inefficient with many equal keys. Another possibility is
> that you're using a non-C locale and strcoll() is horribly slow.
>
> regards, tom lane
>

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