Re: running two instances of pg

Joao Ferreira gmail <joao(dot)miguel(dot)c(dot)ferreira(at)gmail(dot)com> writes:
> So we are considereing separating these two, in order to use 2 diferent
> pg instances. One of the instances will be reniced down in order to
> prevent user access failure during vacuuming and re-indexing operations
> (currently, when we perform database maintenance (we are now at 2Giga
> and growing), several other user related services become inoperative,
> during the maintenance operation, but if we renice the postmaster, the
> users dont experience such a severe service outage)

Have you experimented with the vacuum cost delay settings, instead?
"renice" is not a very good tool for controlling I/O demands.

regards, tom lane