Re: maximum number of databases and / or schemas in a single database instance

Menelaos PerdikeasSemantix <mperdikeas(dot)semantix(at)gmail(dot)com> writes:
> The following page:
> http://www.postgresql.org/about/

> mentions some limits but not the following:

> [1] maximum number of databases per database server instance
> [2] maximum number of schemas per database

> Is there empirical information on whether both these values can be as high
> as a few hundreds? (I don't really need any more for my use case)

You can certainly have hundreds of schemas. I wouldn't really recommend
more than a few dozen databases per instance, though. It tends to bog
down autovacuum, and remember you are storing a separate copy of the
system catalogs per database. You might be able to make a few hundred
databases work all right if you don't mind expending some tuning effort;
but a few thousand is probably right out.

regards, tom lane