Re: Expectations of MEM requirements for a DB with large tables.

 Mike,

> Anyway, I crashed  my system the other  day when I did a  "select *" from
> one
> of my large tables (about 5.5gb in size).

 Well.... It  takes abit more than  that to actually crash  the system. Can
you  give  more details?  What  _exactly_  happened?  Did it  hang?  Kernel
panicked? Something else.

> Does anyone know what  the ratio of data output size  (say from a select)
> to
> the amount of
> RAM used is?

 It simply can't be  other than 1 : 1. Well, in a  sense. Did you use psql?
Other app? If the  latter, what interface: API, DBI, other?  Was it a local
or remote request?

> Other relevant info, RedHat Linux 2.2.17 kernel, PostgreSQL 7.0.2.

 Is this a  genuine kernel, or the  one shipped by RH? Did  you build PGSQL
from sources or  was it a pre-built  binary? How much RAM do  you have, how
fast and big is your swap? Swap settings? Other processes running?
 As you see, there  are more questions than answers at  this stage. Tell us
more. Tuning the system has never been easy.