max_fsm_pages >800k ... ?
Without more information to provide at this time, does the following seem
"unusual"?
INFO: free space map: 252 relations, 411494 pages stored; 738640 total pages needed
DETAIL: Allocated FSM size: 2000 relations + 400000 pages = 2463 kB shared memory.
I know there are alot of factors involved in the above, which I'm looking
into, but when I first saw the above, I just about had a heartattack, only
because i've never seen such high #s for total pages needed ...
... Is this something that others are seeing as relatively normal?
----
Marc G. Fournier Hub.Org Networking Services (http://www.hub.org)
Email: scrappy@hub.org Yahoo!: yscrappy ICQ: 7615664
Marc,
Without more information to provide at this time, does the following
seem "unusual"?INFO: free space map: 252 relations, 411494 pages stored; 738640 total
pages needed DETAIL: Allocated FSM size: 2000 relations + 400000 pages
= 2463 kB shared memory.
Looks like you haven't run VACUUM in a few days. Or like you deleted and
re-loaded a large table multiple times.
BTW, this is really more of a pgsql-performance question ...
--
--Josh
Josh Berkus
Aglio Database Solutions
San Francisco
INFO: analyzing "pg_catalog.pg_depend"
INFO: "pg_depend": 27 pages, 3866 rows sampled, 3866 estimated total
rows
INFO: free space map: 423 relations, 88475 pages stored; 431200 total
pages needed
DETAIL: Allocated FSM size: 4000 relations + 80000 pages = 705 kB
shared memory.
This, on a database with a moderate amount of rows (<10 Million)
So,.. I'd say fairly normal.
... John
Show quoted text
-----Original Message-----
From: pgsql-hackers-owner@postgresql.org
[mailto:pgsql-hackers-owner@postgresql.org] On Behalf Of Marc
G. Fournier
Sent: Thursday, June 16, 2005 3:57 AM
To: pgsql-hackers@postgresql.org
Subject: [HACKERS] max_fsm_pages >800k ... ?Without more information to provide at this time, does the
following seem "unusual"?INFO: free space map: 252 relations, 411494 pages stored;
738640 total pages needed
DETAIL: Allocated FSM size: 2000 relations + 400000 pages =
2463 kB shared memory.I know there are alot of factors involved in the above, which
I'm looking into, but when I first saw the above, I just
about had a heartattack, only because i've never seen such
high #s for total pages needed ...... Is this something that others are seeing as relatively normal?
----
Marc G. Fournier Hub.Org Networking Services
(http://www.hub.org)
Email: scrappy@hub.org Yahoo!: yscrappy
ICQ: 7615664---------------------------(end of
broadcast)---------------------------
TIP 8: explain analyze is your friend
Import Notes
Resolved by subject fallback
"Marc G. Fournier" <scrappy@postgresql.org> writes:
Without more information to provide at this time, does the following seem
"unusual"?
INFO: free space map: 252 relations, 411494 pages stored; 738640 total pages needed
DETAIL: Allocated FSM size: 2000 relations + 400000 pages = 2463 kB shared memory.
What this is saying is that you'd need 738640 fsm_pages slots to
remember every single page that has a useful amount of free space.
However, you don't necessarily have to remember all those pages.
If you remember enough pages to satisfy insert/update requests
until the next VACUUM happens, then you're good.
I think the bottom-line question is "are you seeing any database
bloat?" If yes, increase max_fsm_pages; if no, worry not.
regards, tom lane