Обсуждение: Re: VACUUMing sometimes increasing database size / sometimes

$ ls -al pgsqldb/pg_xlog
total 32816
drwx------    2 nitinverma root         4096 Jun 16 19:53 .
drwx------    6 nitinverma root         4096 Jun 16 19:33 ..
-rw-------    1 nitinverma root     16777216 Jun 16 20:08 0000000000000001
-rw-------    1 nitinverma root     16777216 Jun 16 19:45 0000000000000002

Looks like if a WAL file is created even vacuum can't reclaim the space. Is
that the root cause behind DB bloating with 7.3.2?

-----Original Message-----
From: Richard Huxton [mailto:dev@archonet.com]
Sent: Friday, June 16, 2006 6:29 PM
To: Nitin Verma
Cc: pgsql-general@postgresql.org
Subject: Re: [GENERAL] VACUUMing sometimes increasing database size /
sometimes

Nitin Verma wrote:
>>> if your application depends on things that changed between 7.3 and 8.1.
>>
> Postgres tends to become more strict with every release, so
>>> there are things you got away with in 7.3 which now cause an error
>>> message.
>
> Do we have change lists where I can see all the changes between 7.3 and
8.1,
> may be release by release?

Try the manuals where there are version-by-version details of changes in
the release-notes.

http://www.postgresql.org/docs/8.1/static/release.html

--
   Richard Huxton
   Archonet Ltd

In response to "Nitin Verma" <nitinverma@azulsystems.com>:

> $ ls -al pgsqldb/pg_xlog
> total 32816
> drwx------    2 nitinverma root         4096 Jun 16 19:53 .
> drwx------    6 nitinverma root         4096 Jun 16 19:33 ..
> -rw-------    1 nitinverma root     16777216 Jun 16 20:08 0000000000000001
> -rw-------    1 nitinverma root     16777216 Jun 16 19:45 0000000000000002
>
> Looks like if a WAL file is created even vacuum can't reclaim the space. Is
> that the root cause behind DB bloating with 7.3.2?

All versions of Postgresql generate WAL logs.  This is not bloat, this is
space required for normal operation of the database system.

I believe the defaults are to create 4 files, 16M each, and then rotate
through them.  If you've only got two files so far, this must be a
fairly new installation.

http://www.postgresql.org/docs/8.1/interactive/wal-configuration.html

--
Bill Moran
Collaborative Fusion Inc.