David,
> But, I'm also still interested in the answer to my question: is there
> any reason you could not put an 8.0 tablespace on a RAM disk?
Some people have *talked* about trying it, but nobody yet has reported back.
I can see a few potential problems:
1) The query planner would not be aware, and could not be made aware short of
hacking the source, that one tablespace has different access speeds than the
others;
2) After a crash, you might be unable to recover that tablespace, and PG would
refuse to bring the system back up without it.
However, the best thing to do is to try it. Good luck, and do a write-up for
us!
--
Josh Berkus
Aglio Database Solutions
San Francisco