Re: backup getting larger and larger - Mailing list pgsql-general

From Steve Crawford
Subject Re: backup getting larger and larger
Date
Msg-id 49E4F170.9040403@pinpointresearch.com
Whole thread Raw
In response to backup getting larger and larger  (Ivan Sergio Borgonovo <mail@webthatworks.it>)
Responses Re: backup getting larger and larger
Re: backup getting larger and larger
List pgsql-general
Ivan Sergio Borgonovo wrote:
> I still have to investigate if the tables are getting really
> larger... but at a first guess there shouldn't be any good reason to
> see tables getting so large so fast... so I was wondering if
> anything could contribute to make a backup much larger than it was
> other than table containing more records?
>
> The only thing that should have been really changed is the number of
> concurrent connections during a backup.
>
Can we assume that by backup you mean pg_dump/pg_dumpall? If so, then
the change is likely due to increasing data in the database. I have a
daily report that emails me a crude but useful estimate of table
utilization based on this query:

select
  relname as table,
  to_char(8*relpages, '999,999,999')  as "size (kB)",
  (100.0*relpages/(select sum(relpages) from pg_class where
relkind='r'))::numeric(4,1) as percent
from
  pg_class
where
  relkind = 'r'
order by
  relpages desc
limit 20;


If, however, you are doing a filesystem backup then table and index
bloat could, indeed, increase your backup size. But more importantly,
you will likely be in for a rude surprise should you ever need to restore.

Cheers,
Steve


pgsql-general by date:

Previous
From: Kynn Jones
Date:
Subject: Re: 'no pg_hba.conf entry for host "[local]", user "postgres", database "postgres"'...
Next
From: vj
Date:
Subject: Using CHECK while CREATE'ing table