Re: Space for pg_dump

[Scott Marlowe <scott(dot)marlowe(at)gmail(dot)com>]

On Tue, Mar 31, 2009 at 9:57 AM, SHARMILA JOTHIRAJAH
<sharmi_jo(at)yahoo(dot)com> wrote:
> But I need to pre-allocate some space for storing these dumps (there are other databases too that needs to be dumped). So Im trying to find a space estimate ....
> Do you have a rough estimate of pg_dump in general... like 1/4 th of the database size or something like that...I just need a rough estimate for now

Sadly, there is no exact maths for such things.  If your database has
tons of indexes and such, it might be 20 or 100 times bigger on disk
than it will be during backup.  If it's all compressible text with few
indexes, it might be a 1:1 or so size.  You can't really tell without
running pg_dump.  The advantage of doing pg_dump|wc -l is that the db
doesn't have to be stored somewhere.