Обсуждение: Advice request: Postgresql setup for flash memories.

Hello,

 since flash memory hardware is dropping prices at
high rate I was planning to test how Postgresql runs
in such hardware.

 For all I have read, main difference between Hard
disc storage and flash memory is that of seek time,
beeing flash memory card seek time much faster since
it lacks mechanical parts. My intution says that such
fact must have depth inpact on how databases "tunning
parameters" are setup.

 Anyone has any experience in "tunning" Postgresql for
Flash memories.


 Thanks in advance for any help, hint or link.

 Enrique

=?iso-8859-1?q?Enrique=20Ariz=F3n?= <e_arizon_benito@yahoo.com> writes:
>  since flash memory hardware is dropping prices at
> high rate I was planning to test how Postgresql runs
> in such hardware.

This is probably a bad idea, unless the number-of-write-cycles
limitation of flash memory has gone away while I wasn't looking.
PG is pretty piggy as far as rewriting disk pages goes, especially
for the WAL files.

            regards, tom lane

On Sun, 2006-08-27 at 16:45, Tom Lane wrote:
> =?iso-8859-1?q?Enrique=20Ariz=F3n?= <e_arizon_benito@yahoo.com> writes:
> >  since flash memory hardware is dropping prices at
> > high rate I was planning to test how Postgresql runs
> > in such hardware.
>
> This is probably a bad idea, unless the number-of-write-cycles
> limitation of flash memory has gone away while I wasn't looking.
> PG is pretty piggy as far as rewriting disk pages goes, especially
> for the WAL files.

Note that most flash memory controllers randomize the accesses across
the media to prevent / slow this problem.  So, it's critical that IF one
has a pg store on a flash device that it have a controller that spreads
writes around.  Without that, your flash memory will fail fairly soon.