Thanks for the answer! About you questions: 1. Postgres 9.3 2. There are about 30-50 user connections. Actually Only 2 of databases are used intensively, others only in rare cases. 3. Hardware is AMD Phenom II X4 965, 8 Gb RAM, 2 SATA2 HDD in software mirror raid 4. The reason to switch to multiple clusters is that my software uses roles (login users and groups) for a single database. There are some problems with it in case of several databases because in postgres roles are shared between all the databases in the same cluster. 28.09.2013, 22:29, "Tomas Vondra" <tv@xxxxxxxx>: > On 28 Září 2013, 20:12, Eugene Ostrovsky wrote: > >> Hello! >> >> I would like to find out what is the difference in hardware resources >> consuming between two solutions: >> 1. Several databases in the same postgresql cluster >> 2. Several clusters (one per each database) on the same host >> >> Currently I have about 10 databases in the same cluster. For some reasons >> I'm going to switch to using separate clusters on the same machine. I >> suspect that this could affect the performance. >> >> Any ideas on how much more hardware resources will be consumed? > > Well, that's hard to say because we don't know (a) the version of > PostgreSQL you're using, (2) how you use it and (c) what hardware you use. > > There are probably some corner cases where this might improve the > performance, but in most cases it's going to be worse. Why are you > switching to multiple clusters? > > For example consider that you'll probably have to use much smaller shared > buffers (which might cause issues on the active database, while the other > databases don't use their portion of memory), you'll have to either use > much smaller max_connections or decrease work_mem (you can't just keep the > values because then you might run into OOM much more frequently) etc. > > Tomas -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
