Re: [BULK] Problems with vacuum! - Mailing list pgsql-performance

From Domenico Sgarbossa
Subject Re: [BULK] Problems with vacuum!
Date
Msg-id 011101c4553b$c1967130$70c8007e@xtecnica.it
Whole thread Raw
In response to Re: [BULK] Problems with vacuum!  ("Domenico Sgarbossa" <domenico@xtecnica.com>)
Responses Re: [BULK] Problems with vacuum!  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-performance
The problems still remains...
I've tried to change shmax to 128 mb (i've got 2 GB of ram),
then the others parameter are set as follow:

shared_buffers = 8096        # 2*max_connections, min 16
max_fsm_relations = 500    # min 10, fsm is free space map
max_fsm_pages = 15000      # min 1000, fsm is free space map
max_locks_per_transaction = 64 # min 10
wal_buffers = 8            # min 4

#
#       Non-shared Memory Sizes
#
sort_mem = 1024          # min 32
vacuum_mem = 16384          # min 1024

I've scheduled 2 tasks nightly:

vacuumdb --analyze dbname
pg_dump -x -f dbname.dmp dbname

so when the users go home, i've got something like 15/20000kb free ram, the
rest is cached and 0kb of swap...
It seems that when pg_dump starts the cached memory isn't released so the
system begin to swap, then the system
does the same with vacuum..... even if there 1.8 gb of cached ram (that
is'nt released anymore....) very strange!

anyone could explain mw why this happend?


Distinti Saluti

Sgarbossa Domenico
X Tecnica S.R.L.
www.xtecnica.com
Tel: 049/9409154 - 049/5970297
Fax: 049/9400288





pgsql-performance by date:

Previous
From: pginfo
Date:
Subject: Re: Major differences between oracle and postgres performance
Next
From: Richard Huxton
Date:
Subject: Re: Major differences between oracle and postgres performance