Re: Multiple disks

On Thu, 8 Apr 2004, hal wrote:

> What is the best/simplest way to split:
>     a database
>     multiple databases
>     a table
>     multiple tables
> across more than one disk drive?
>
> I know that this has come up before but I can't find
> any info.  A pointer to a HOWTO or other info would
> be wonderful.

The current king of putting postgresql on multiple platters and getting
best overall performance is a battery backed caching raid controller run
one or more many disk RAID-5 arrays.  The more disks, the better up to a
dozen or two.

The red headed step child is the alternate location stuff, discussed in
the docs here:
http://www.postgresql.org/docs/7.4/static/manage-ag-alternate-locs.html
which will allow you to put individual databases in different locations.
It's a hackish kludge that should be replaced by the upcoming tablespaces
patches.  I'm not sure if those will be done by 7.5 release or not.

The next way is to individually link thinks like indexes onto other
volumes.  The procedure is basically, create the index, figure out which
file in $PGDATA/base/oidofyourdbhere is the index, shut down postgresql,
copy to file elsewhere, softlink it, restart apache.  This setup will not
survive reindexing or dropping / recreating the index.