On Mon, 25 Aug 2003, Stephan Szabo wrote:
> Date: Mon, 25 Aug 2003 00:43:56 -0700 (PDT)
> From: Stephan Szabo <sszabo@megazone.bigpanda.com>
> To: mike <mike@Reifenberger.com>
> Cc: pgsql-bugs@postgresql.org
> Subject: Re: [BUGS] index not used afer VACUUM ANALYZE
>
> On Thu, 21 Aug 2003, mike wrote:
>
> > Hi,
> > I hav a db as specified in nit.sql
> > flows has 763488 entries.
> >
> > After dropping/creating/loading the db and running auswert.sh I get
> > the attached result from query1.txt.
> > After 'VACUUM ANALYZE' I get the results from query2.txt
> >
> > As you can see, the indexes are not used any longer.
> > Why?
>
> It looks like the row estimates changed to say that a large % of the rows
> match the condition. Is that true? In any case, what does EXPLAIN
Partially.
I have statistical records (763488) - various IP-Traffic - collected for one
month.
After collection I try to condense the data for dayly statistics.
The EXPLAIN ANALYZE output is attached:
a1.txt is before, a2.txt after VACUUM ANALYZE run.
Bye/2
---
Michael Reifenberger, Business Unit Manager SAP-Basis, Plaut Consulting
Comp: Michael.Reifenberger@plaut.de | Priv: Michael@Reifenberger.com
http://www.plaut.de | http://www.Reifenberger.com