Re: VACUUM FULL on 24/7 server

Christopher Browne wrote:
 > aserba@gmail.com (Aleksey Serba) wrote:
 >
 >>   Hello!
 >>
 >>   I have 24/7 production server under high load.
 >>   I need to perform vacuum full on several tables to recover disk
 >>   space / memory  usage frequently ( the server must be online during
 >>   vacuum time )
 >
 >
 > The main thought is: "Don't do that."
 >
 > It is almost certainly the wrong idea to do a VACUUM FULL.
 >
 > Assuming that the tables in question aren't so large that they cause
 > mass eviction of buffers, it should suffice to do a plain VACUUM (and
 > NOT a "VACUUM FULL") on the tables in question quite frequently.

This is easy to say and almost impraticable. I run a 7.4.5 with the autovacuum:

pg_autovacuum -d 3 -v 300 -V 0.5 -S 0.8 -a 200 -A 0.8

I have also a "vacuumdb -z -v -a"  running each six hours and if i don't execute
a vacuum FULL for one weeks I collect almost 400 MB of dead rows :-(
For this reason even with a 7.4.5 I'm obliged to run a vacuum full at least once
a week and a reindex once a month.

And my FSM parameters are large enough:

INFO:  free space map: 141 relations, 26787 pages stored; 26032 total pages needed
DETAIL:  Allocated FSM size: 1000 relations + 2000000 pages = 11780 kB shared memory.


Regards
Gaetano Mendola

PS: I do not have any "idle in transaction" connections around.