RE: Max# of tablespaces

Excellent - thanks for the fast response - it was an oracle dba that set it up initially so that may explain it -

Thanks very much

-----Original Message-----
From: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
Sent: Sunday, January 3, 2021 12:27 PM
To: Thomas Flatley <FLATLEYT(at)outlook(dot)com>
Cc: pgsql-general(at)lists(dot)postgresql(dot)org
Subject: Re: Max# of tablespaces

Thomas Flatley <FLATLEYT(at)outlook(dot)com> writes:
> Hello, I've checked the docs but cant seem to find if there is a max # of tablespaces allowed - I've come across a 9.5 env with 1600 tablespaces - they want to double that - Oracle's max is 64k, I'm not particularly worried about hitting a wall, if there is one , outside of maintenance issues - any assistance would be greatly appreciated.

There's no particular hard limit, though you might start to run into OID-starvation problems at a billion or so tablespaces.

On the other hand, it's important to realize that a Postgres tablespace doesn't really *do* anything. It's just a separate subdirectory.
The only functional reason to use a tablespace is if you can place it on a separate filesystem. There is certainly value in being able to do that --- but I've never heard of systems having more than a few dozen filesystems mounted. Hence, the above issue sounds suspiciously like somebody is expecting Postgres tablespaces to do something they don't do.

(I suppose if you are working on a system that has limits on the number of files per directory, or performance problems with large values of that, then you could use tablespaces as a workaround.
But TBH you'd be better off moving onto a more modern platform.)

regards, tom lane