Thread: running only pg_autovacuum for one week

running only pg_autovacuum for one week

From
Gaetano Mendola
Date:
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Hi all,
I did the experiment of running only the autovacuum for one week without
running my daily autovacuum full and reindex on heavy updated/inserted
tables.
Yesterday I reenabled the vacuum full and reindex and, as you can see
from the attachment, I recover 600MB of wasted space.




Regards
Gaetano Mendola





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Attachment

Re: running only pg_autovacuum for one week

From
"Scott Marlowe"
Date:
On Mon, 2004-08-02 at 07:08, Gaetano Mendola wrote:
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> Hi all,
> I did the experiment of running only the autovacuum for one week without
> running my daily autovacuum full and reindex on heavy updated/inserted
> tables.
> Yesterday I reenabled the vacuum full and reindex and, as you can see
> from the attachment, I recover 600MB of wasted space.

autovacuum is a daemon.  You don't run it once a week, you set it loose
and forget about it.  Unless you're running it then shutting it down,
running once a week is unnecessary.

Also, what are you fsm settings in the postgresql.conf file?


Re: running only pg_autovacuum for one week

From
Gaetano Mendola
Date:
Scott Marlowe wrote:> On Mon, 2004-08-02 at 07:08, Gaetano Mendola wrote:>>>-----BEGIN PGP SIGNED MESSAGE----->>Hash:
SHA1>>>>Hiall,>>I did the experiment of running only the autovacuum for one week without>>running my daily autovacuum
fulland reindex on heavy updated/inserted>>tables.>>Yesterday I reenabled the vacuum full and reindex and, as you can
see>>fromthe attachment, I recover 600MB of wasted space.>>> autovacuum is a daemon.  You don't run it once a week, you
setit loose> and forget about it.  Unless you're running it then shutting it down,> running once a week is unnecessary. 

Sorry, I meant that I had running "only" the pg_autovacuum for the entire week,
without run also my vacuum full + reindex once a day. I was only stopping it and
rerunning for logrotation purpose.
Analyzing the graph on Wednedsay I had a few of processes in "idle in transaction"
state and as you can see the graph had a big ramp and that space was not reclamed
till this morning :-(
> Also, what are you fsm settings in the postgresql.conf file?

At the end of my autovacuum full I have:

INFO:  free space map: 603 relations, 38202 pages stored; 40592 total pages needed
DETAIL:  Allocated FSM size: 1000 relations + 2000000 pages = 11780 kB shared memory.


So I think that I'm not reaching the limits.


As explained in another thread untill I can not set the "threasholds" per table
the autovacuum is useless ( milions rows tables with hundred of insert per day ).


Regards
Gaetano Mendola