Re: 12 hour table vacuums - Mailing list pgsql-performance

From Joshua D. Drake
Subject Re: 12 hour table vacuums
Date
Msg-id 20071023104113.1f4d0aa0@scratch
Whole thread Raw
In response to Re: 12 hour table vacuums  (Ron St-Pierre <ron.pgsql@shaw.ca>)
List pgsql-performance
On Tue, 23 Oct 2007 10:00:05 -0700
Ron St-Pierre <ron.pgsql@shaw.ca> wrote:

> Alvaro Herrera wrote:
> > Ron St-Pierre wrote:
> >
> >
> >> Okay, here's our system:
> >>   postgres 8.1.4
> >>
> >
> > Upgrade to 8.1.10
> >
> Any particular fixes in 8.1.10 that would help with this?
> >
> >> Here's the table information:
> >> The table has 140,000 rows, 130 columns (mostly NUMERIC), 60
> >> indexes.
> >
> > 60 indexes?  You gotta be kidding.  You really have 60 columns on
> > which to scan?
> >
> >
> Really. 60 indexes. They're the most commonly requested columns for
> company information (we believe). Any ideas on testing our
> assumptions about that? I would like to know definitively what are
> the most popular columns. Do you think that rules would be a good
> approach for this? (Sorry if I'm getting way off topic here)

I suggest you:

1. Turn on stats and start looking in the stats columns to see what
indexes are actually being used.

2. Strongly review your normalization :)

Joshua D. Drake



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