Re: FYI: Load times for a largish DB in 8.2 vs. 8.3 vs. 8.4

There was an interesting presentation at PG Con from a guy at Sun who
did a series of load tests on 8.3 vs 8.4

http://www.pgcon.org/2009/schedule/events/124.en.html

There is a link to the video from that page so you can watch it.  But
he found a strange "corner case" where 8.4 performed way worse.  After
he did a bit of digging he found a  couple of default settings that
had changed in 8.4, and when he set them back to their old 8.3 values
and re-ran the tests, there was a huge difference in outcome.



On Wed, Jun 17, 2009 at 10:50 AM, Todd A.
Cook<tcook@blackducksoftware.com> wrote:
> Hi,
>
> First, the numbers:
>
>  PG Version    Load time     pg_database_size     autovac
> ----------------------------------------------------------
>  8.2.13        179 min       92,807,992,820        on
>  8.3.7         180 min       84,048,744,044        on (defaults)
>  8.4b2         206 min       84,028,995,344        on (defaults)
>  8.4b2         183 min       84,028,839,696        off
>
> The bulk of the data is in 16 tables, each having about 55 million rows of
> the form (int, int, smallint, smallint, int, int, int).  Each table has a
> single partial index on one of the integer columns.  The dump file was 14GB
> compressed.
>
> The loads were all done on the same machine, with the DB going on a pair
> of SATA drives in a RAID-0 stripe.  The machine has 2 non-HT Xeons and
> 8GB RAM.  maintenance_work_mem was set to 512MB in all three cases.
>
> -- todd
>
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