Postgres Pro
Downloads
Home   >   mailing lists

Thread: Max Number of Databases on a Server.

Max Number of Databases on a Server.

From
daleedom@hightowergroup.com (David A. Leedom)
Date:
What is the practical limit of Postgres Databases on one typical PC
class Linux server?

If I created 100 separate databases on a Linux Server would this be a
problem?  Or is the issue more related to concurrent connections?

Re: Max Number of Databases on a Server.

From
Tom Lane
Date:
daleedom@hightowergroup.com (David A. Leedom) writes:
> If I created 100 separate databases on a Linux Server would this be a
> problem?  Or is the issue more related to concurrent connections?

If you're talking about multiple databases served by a single
postmaster, I don't believe it's much of an issue.  You might start to
notice performance problems when you got past a few thousands, but
that'd have more to do with kernel performance (slow lookup for many
files in one directory) than Postgres itself.

Concurrent connections is a much more interesting question, but no one
can give you any interesting answers without a lot more assumptions
than "typical Linux server".  How much iron is that really, and what
are your concurrent users going to be doing?

            regards, tom lane

Vacuum blocking...

From
Jean-Arthur Silve
Date:
Hello !

I used to run vacuum verbose analyze (vacuumdb -v -a -z) every days.
Everything was ok for months until yesterday !

Usually, this command takes about 1 mn.

Now, vacuum "blocks" on one table (apparently "comptes" table) , without HD
activity, no error message....

avr 15 10:31:27 uranus logger: NOTICE:  --Relation comptes--
avr 15 10:31:27 uranus logger: NOTICE:  Pages 492: Changed 26, reaped 491,
Empty 0, New 0; Tup 6900: Vac 6229, Keep/VTL 0/0, Crash 0, UnUsed 694,
MinLen 242, MaxLen 698; Re-using: Free/Avail. Space 1946648/1943020;
EndEmpty/Avail. Pages 0/456. CPU 0.04s/0.27u sec.

Then, nothing happens...

Any idea ?
PS : I use 7.0 version

jean-arthur

Re: Vacuum blocking...

From
Tom Lane
Date:
Jean-Arthur Silve <jeanarthur@eurovox.fr> writes:
> Now, vacuum "blocks" on one table (apparently "comptes" table) , without HD
> activity, no error message....

Curious.  Do you want to get in there with a debugger and see where it's
looping?

> PS : I use 7.0 version

Hmm ... are you on 7.0.3?  There's a known bug in earlier releases that
could perhaps lead to an endless loop in VACUUM.

The simplest answer is probably "past time to update to 7.2.1", anyway.

            regards, tom lane