Re: DB Dump Size

On Thu, Aug 14, 2008 at 12:06:53PM +1000, steve(at)outtalimits(dot)com(dot)au wrote:
> Hi all,
>
> I am curious as to why a pg dump of database "name" is 2.9gig. But is
> measured at 1.66gig by:
> SELECT pg_database_size(pg_database.datname) AS db_size FROM pg_database
> WHERE pg_database.datname='name' ;
>
> This dump was about 1 gig around 12 months ago.

Which options do you use for pg_dump? And what version of PosgreSQL are
you running?

In general it's not that strange for an uncompressed
dump to be larger than the database size, plain SQL
dumps are much less space efficient than a DBMS can
be when it stores the data on disk. But of course, there
also indices to consider.

Have you tried pg_dump -Fc?

> I am performing a monthly vacuum full on the database and a nightly vacuum
> all

That should only impact the pg_database_size.