Daniel Freedman wrote:
>
> On the topic of query cache (or maybe this is just tangential and I'm
> confused):
>
> I've always heard that Oracle has the ability to essentially suck in as
> much of the database into RAM as you have memory to allow it, and can then
> just run its queries on that in-RAM database (or db subset) without doing
> disk I/O (which I would probably imagine is one of the more expensive
> parts of a given SQL command). I've looked for references as to
> Postgresql's ability to do something like this, but I've never been
> certain if it's possible. Can postgresql do this, please? And, if not,
> does it have to hit the disk for every SQL instruction (I would assume
> so)?
PostgreSQL hits the disk on UPDATE/DELETE/INSERT operations. SELECT's
are cached, but the default cache is only ½MB of RAM. You can change
this to whatever you want.
I'm using Cold Fusion and it can cache queries itself, so no database
action is necessary. But I don't think PHP and others have this
possibility. But Cold Fusion costs 1300$ :(
Poul L. Christiansen
