Re: Space for pg_dump

--- On Tue, 3/31/09, Scott Marlowe <scott.marlowe@gmail.com> wrote:

> From: Scott Marlowe <scott.marlowe@gmail.com>
> Subject: Re: [GENERAL] Space for pg_dump
> To: "SHARMILA JOTHIRAJAH" <sharmi_jo@yahoo.com>
> Cc: "General postgres mailing list" <pgsql-general@postgresql.org>
> Date: Tuesday, March 31, 2009, 12:07 PM
> On Tue, Mar 31, 2009 at 9:57 AM,
> SHARMILA JOTHIRAJAH
> <sharmi_jo@yahoo.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.
>
Thanks...I started pg_dump|wc -l  and its running now
Another question is that wc -l gives you the no of lines...right...
What is the size of each line...or how do you get the size from that?