Thread: WAL on a RAM disk
As part of our application we are running a postgres server on a RAM disk. All of the data stored in this database is obviously disposable, and we need to optimize access as much as possible. This is on Solaris 9/intel, postgres 7.4.5. Some things I'm wondering about:
1) is it possible to turn off WAL entirely? If not, what configuration of WAL/Checkpoint settings would result in minimal WAL activity?
2) Given that the whole database is in memory, does it make sense to set random_page_cost to a high value...or, um... a low value? (Does it show that I don't understand this parameter?)
3) Any other settings I should be looking at?
Thanks. I don't know if anybody else has done this, but I'd be interested to hear about it, if so.
- DAP
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David Parker Tazz Networks (401) 709-5130
David Parker wrote: > As part of our application we are running a postgres server on a RAM > disk. All of the data stored in this database is obviously disposable, > and we need to optimize access as much as possible. This is on Solaris > 9/intel, postgres 7.4.5. Some things I'm wondering about: > > 1) is it possible to turn off WAL entirely? No. > If not, what configuration of WAL/Checkpoint settings would result in > minimal WAL activity? You could turn off fsync. > > 2) Given that the whole database is in memory, does it make sense to > set random_page_cost to a high value...or, um... a low value? (Does it > show that I don't understand this parameter?) Low. > > 3) Any other settings I should be looking at? > > Thanks. I don't know if anybody else has done this, but I'd be > interested to hear about it, if so. You could get a small solid state disk and put your wal on that. Sincerely, Joshua D. Drake > - DAP > ---------------------------------------------------------------------------------- > David Parker Tazz Networks (401) 709-5130 > > > -- Command Prompt, Inc., home of Mammoth PostgreSQL - S/ODBC and S/JDBC Postgresql support, programming shared hosting and dedicated hosting. +1-503-667-4564 - jd@commandprompt.com - http://www.commandprompt.com PostgreSQL Replicator -- production quality replication for PostgreSQL
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* David Parker (dparker@tazznetworks.com) wrote:
> As part of our application we are running a postgres server on a RAM
> disk. All of the data stored in this database is obviously disposable,
> and we need to optimize access as much as possible. This is on Solaris
> 9/intel, postgres 7.4.5. Some things I'm wondering about:
>
> 1) is it possible to turn off WAL entirely? If not, what configuration
> of WAL/Checkpoint settings would result in minimal WAL activity?
I doubt you can turn it off... I would guess that a larger number of
WAL logs would reduce the recycling which would require slightly less
activity, I think, but it'd take up memory space, so...
> 2) Given that the whole database is in memory, does it make sense to set
> random_page_cost to a high value...or, um... a low value? (Does it show
> that I don't understand this parameter?)
Should be a lower value, it's a 'cost'.
> 3) Any other settings I should be looking at?
>
> Thanks. I don't know if anybody else has done this, but I'd be
> interested to hear about it, if so.
Please send results you find to the list, I'm certainly interested in
hearing how this turns out...
Stephen