Re: 12 hour table vacuums - Mailing list pgsql-performance

In response to Ron St-Pierre <ron.pgsql@shaw.ca>:

> We vacuum only a few of our tables nightly, this one is the last one
> because it takes longer to run. I'll probably re-index it soon, but I
> would appreciate any advice on how to speed up the vacuum process (and
> the db in general).

I doubt anyone can provide meaningful advice without the output of
vacuum verbose.

>
> Okay, here's our system:
>    postgres 8.1.4
>    Linux version 2.4.21
>    Red Hat Linux 3.2.3
>    8 GB ram
>    Intel(R) Xeon(TM) CPU 3.20GHz
>    Raid 5
>    autovacuum=off
>    serves as the application server and database server
>    server is co-located in another city, hardware upgrade is not
> currently an option
>
> Here's the table information:
> The table has 140,000 rows, 130 columns (mostly NUMERIC), 60 indexes. It
> is probably our 'key' table in the database and gets called by almost
> every query (usually joined to others). The table gets updated only
> about 10 times a day. We were running autovacuum but it interfered with
> the updates to we shut it off. We vacuum this table nightly, and it
> currently takes about 12 hours to vacuum it. Not much else is running
> during this period, nothing that should affect the table.
>
> Here are the current non-default postgresql.conf settings:
> max_connections = 100
> shared_buffers = 50000
> work_mem = 9192
> maintenance_work_mem = 786432
> max_fsm_pages = 70000
> vacuum_cost_delay = 200
> vacuum_cost_limit = 100
> bgwriter_delay = 10000
> fsync = on
> checkpoint_segments = 64
> checkpoint_timeout = 1800
> effective_cache_size = 270000
> random_page_cost = 2
> log_destination = 'stderr'
> redirect_stderr = on
> client_min_messages = warning
> log_min_messages = warning
> stats_start_collector = off
> stats_command_string = on
> stats_block_level = on
> stats_row_level = on
> autovacuum = off
> autovacuum_vacuum_threshold = 2000
> deadlock_timeout = 10000
> max_locks_per_transaction = 640
> add_missing_from = on
>
> As I mentioned, any insights into changing the configuration to optimize
> performance are most welcome.
>
> Thanks
>
> Ron
>
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>
>
>
>
>


--
Bill Moran
Collaborative Fusion Inc.
http://people.collaborativefusion.com/~wmoran/

wmoran@collaborativefusion.com
Phone: 412-422-3463x4023

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