Re: [pgsql-general] In memory tables/databases

On 7/2/07, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
> David Fetter <david(at)fetter(dot)org> writes:
> > On Sun, Jul 01, 2007 at 03:55:11PM -0400, Alvaro Herrera wrote:
> >> So mount a ramdisk and initdb in there.
>
> > You could also put a tablespace on a ramdisk and create the table
> > there.

Thanks for this hint. That looks like what I was looking for.

>
> The fresh-initdb approach is more likely to work without any strange
> corner cases. If you try a setup where the system catalogs are on
> persistent storage but you have a tablespace on ramdisk, then after
> restart you'll have pg_class entries referencing files that don't exist
> anymore, which I believe will provoke errors.

I believe error will occur if trying to access these objects. To avoid
this pg_dump/pg_restore may be useful and recreating the
tables/indexes after restart.
This will emulate the MySQL behaviour where tables definitions is kept
on disk and contents kept in memory.