Re: Excessive rows/tuples seriously degrading query

Chadwick, Russell kirjutas L, 13.12.2003 kell 00:40:
>
> Hello everyone.
> Can anyone explain why this table which has never had more than a
> couple rows in it shows > 500k in the query planner even after running
> vacuum full. Its terribly slow to return 2 rows of data. The 2 rows
> in it are being updated a lot but I couldn't find any explanation for
> this behavior.

It can be that there is an idle transaction somewhere that has locked a
lot of rows (i.e. all your updates have been running inside the same
transaction for hour or days)

try:
$ ps ax| grep post

on my linux box this gives

1683 ? S 0:00 /usr/bin/postmaster -p 5432
1704 ? S 0:00 postgres: stats buffer process
1705 ? S 0:00 postgres: stats collector process
5520 ? S 0:00 postgres: hu hannu [local] idle in transaction
5524 pts/2 S 0:00 grep post

where backend 5520 seems to be the culprit.

> Anything I could try besides droping db and recreating?

make sure that no other backend is connected to db and do your
> vacuum full; analyze;

or if there seems to be something unidentifieable making your table
unusable, then just recreate that table:

begin;
create table stock_log_positions_tmp
as select * from stock_log_positions;
drop table stock_log_positions;
alter table stock_log_positions_tmp
rename to stock_log_positions;
-- if you have any constraints, indexes or foreign keys
-- then recreate them here as well
commit;

> Thanks - Russ
>
---------------
hannu