Re: transactoin id wraparound problem - Mailing list pgsql-admin

From Sriram Dandapani
Subject Re: transactoin id wraparound problem
Date
Msg-id 6992E470F12A444BB787B5C937B9D4DF05ABC91A@ca-mail1.cis.local
Whole thread Raw
In response to transactoin id wraparound problem  ("Sriram Dandapani" <sdandapani@counterpane.com>)
Responses Re: transactoin id wraparound problem  (Alvaro Herrera <alvherre@commandprompt.com>)
List pgsql-admin
Hi
I have several such databases to issue vacuum on. If I were to vacuum
each table individually, would the transaction id be updated after every
table vacuum.

Wonder if it is because I have several large partitioned tables that I
drop every day that don't get vacuumed enough.

-----Original Message-----
From: Scott Marlowe [mailto:smarlowe@g2switchworks.com]
Sent: Wednesday, September 06, 2006 2:18 PM
To: Sriram Dandapani
Cc: Tom Lane; pgsql-admin@postgresql.org
Subject: RE: [ADMIN] transactoin id wraparound problem

On Wed, 2006-09-06 at 16:06, Sriram Dandapani wrote:
> Curious why autovacuum does not handle this problem. Here are my
> settings
>
> max_fsm_pages = 2000000
>
> autovacuum = on                                # enable autovacuum
>
> autovacuum_naptime = 300                # time between autovacuum
runs,
> in
>
> autovacuum_vacuum_threshold = 10000     # min # of tuple updates
before
>                                         # vacuum
> autovacuum_analyze_threshold = 1500     # min # of tuple updates
before
>                                         # analyze
> autovacuum_vacuum_scale_factor = 0.4    # fraction of rel size before
>                                         # vacuum
> autovacuum_analyze_scale_factor = 0.2   # fraction of rel size before
>                                         # analyze
> autovacuum_vacuum_cost_delay = 100
>
> autovacuum_vacuum_cost_limit = 1000
>
>
> The database has a constant rate of about 50-100G a day of data
flowing
> in which gets deleted after 2 days.(this cycle keeps repeating). There
> are historical tables that grow at a rate of 2G-4G a day

The most common cause of these problems is that you have long standing
transactions that never get closed.  Look for some connection to the
database(s) (any of them) that are never committed or rolled back.  One
"idle in transaction" connection from one program can cause this
problem.

If you're doing your updates and / or deletes individually instead of in
transactional batches that will just make it worse.



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