Re: Sudden drop in DBb performance

> That's a good thought,  maybe the stats are old and you have bad
> plans?  It could also be major updates to the data too (as opposed to
> growth).

we have made checks for number of dead tuples etc recently, but looks
ok. and as "everything" in the database seems to be very slow atm, I
guess the problem is not caused by bad plans for specific tables/queries.
>
> Gerhard, have you done an 'explain analyze' on any of your slow
> queries?   Have you done an analyze lately?
>

yes we added the 'auto_explain' module to log/analyze queries >= 5000ms.
a sample result from the logs (there is lots of stuff in the logs, I
selected this query because it is very simple):

2011-09-06 04:00:35 CEST ANWEISUNG:  INSERT into
keywords.table_x_site_impact (content_id, site_impact_id, site_impact)
VALUES (199083087, 1, 1.000000)
2011-09-06 04:00:35 CEST LOG:  Dauer: 15159.723 ms  Anweisung: INSERT
into keywords.table_x_site_impact (content_id, site_impact_id,
site_impact) VALUES (199083087, 1 , 1.000000)
2011-09-06 04:00:35 CEST LOG:  duration: 15159.161 ms  plan:
         Result  (cost=0.00..0.01 rows=1 width=0) (actual
time=0.017..0.019 rows=1 loops=1)
           Output:
nextval('keywords.table_x_site_impact_internal_id_seq'::regclass),
199083087::bigint, 1::smallint, 1::double precision