Hello Kevin,
On 03/29/2011 09:28 PM, Kevin Grittner wrote:
Lars Feistner<feistner@xxxxxxxxxxxxxxxxx> wrote:
The log tells me that certain update statements take sometimes
about 3-10 minutes. But we are talking about updates on tables
with 1000 to 10000 rows and updates that are supposed to update 1
row.
The top possibilities that come to my mind are:
(1) The tables are horribly bloated. If autovacuum is off or not
aggressive enough, things can degenerate to this level.
Some tables are auto vacuumed regularly others are not. The specific
table extjs_recentlist was never autovacuumed. So i would think that
updates on this table should be always very slow, but they are not. Only
every 4 or 5th day for maybe half an hour and then everything is fine
again. And;-) there is no anti virus installed.
(2) Memory is over-committed and your machine is thrashing.
We can rule this out. There is enough memory installed and the database
is less than 500MB.
(3) There are explicit LOCK commands in the software which is
contributing to the blocking.
We use the the jdbc driver. The jdbc driver might do some locking but we
don't.
(4) There is some external delay within the transaction, such as
waiting for user input while the transaction is open.
No, no user interaction within a transaction.
Maybe there's a combination of the above at play. Can you rule any
of these out?
-Kevin
So, i will try to get the autovacuum to be more aggressive and will
report again if nothing changes.
Thanks a lot.
Lars
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Lars Feistner
Kompetenzzentrum fÃr PrÃfungen in der Medizin
Medizinische FakultÃt Heidelberg,
Im Neuenheimer Feld 346, Raum 013
69120 Heidelberg
E-Mail: feistner@xxxxxxxxxxxxxxxxx
Fon: +49-6221-56-8269
Fax: +49-6221-56-7175
WWW: http://www.ims-m.de
http://www.kompmed.de
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