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