Message-ID: <46080037.9020209@designaproduct.biz>
Date: Mon, 26 Mar 2007 19:17:43 +0200
From: Laszlo Nagy <gandalf@designaproduct.biz>
User-Agent: Thunderbird 1.5.0.10 (Windows/20070221)
MIME-Version: 1.0
To: pgsql-admin@postgresql.org
Subject: autovacuum question
Content-Type: text/plain; charset=ISO-8859-2; format=flowed
Content-Transfer-Encoding: 7bit


  Hello,

I had a problem in my computer system yesterday. Some data has 
disappeared. I was looking for a program that might have deleted it 
accidentally. Before I found anything, the data suddenly came back. I 
thought it must be a transaction id wraparound problem.

The system is running on FreeBSD 6.2. Postgresql version is 8.1.8 and it 
was installed from FreeBSD's standard ports tree. It also installed a 
script that vacuums all databases daily. This script was turned on, and 
I got emails every day, telling me that the databases were vacuumed. 
However, when I opened some tables from within pgadmin3, I got the 
message "pg_autovacuum recommened".

Summary: I'm vacuuming all databases daily, but probably I had a 
transaction wraparound.

I thought I should enable autovacuum. I read the docs and did the following:

1. Changed postgresql.conf:

stats_start_collector = on
stats_row_level = on
autovacuum = on

2. Restarted the postgresql service.

Now, I do not see a "separate autovacuum daemon" running. What did I 
wrong? Here are my tips:

a.) atovacuum daemon is part of the "postgres" process, so I won't see 
it running in the process list (how can I check if it is working?)
b.) there is a separate program that I should start (where?)
c.) I missed some extra configuration (what should I do?)
d.) something else

Please help me out.
Thanks,

   Laszlo