On 19 May 2011 04:08, Craig Ringer <craig@xxxxxxxxxxxxxxxxxxxxx> wrote:
On 05/19/2011 04:33 AM, Szymon Guz wrote:
<mailto:ipluta@xxxxx>> wrote:
 ÂW dniu 2011-05-18 13:21, Szymon Guz pisze:
   ÂHi,
   ÂI've got a question about quite a strange configuration.
   ÂI was asked if we can have one storage, with one data directory
   Âwhere one postgresql instance writes data, and many other
   Âinstances read those.
   ÂIs that possible without any replication and copying data?
 ÂWhy do they think they need that?
They've got some quite nice and huge storage and it would be nice to use
it from many different machines running postgreses.
Another option is Oracle which can do that.
If you're thinking of Oracle RAC: be careful. Anecdotal reports I've heard suggest that a RAC cluster needs to be about 3 machines before it equals the performance of a single standalone Oracle instance on same kind of hardware. I have no personal experience with this, though, and am under the impression that the people I've heard talking about it were referring to multi-master setups. It's possible that single-master setups with read-only slaves are more efficient. It's also possible that they were just wrong. All I'm saying is that you should investigate carefully.
--
Craig Ringer
Hi,
thanks for the answer. It is not a problem to have 3 oracle instances, in fact there will be hundreds of them probably, but could also be hundreds of Postgres instances :)Â
regards
Szymon
