Re: wal_level and continuous archiving documentation

On Fri, May 14, 2010 at 1:42 AM, Joshua Tolley <eggyknap(at)gmail(dot)com> wrote:
> I was reading through
> http://www.postgresql.org/docs/9.0/static/continuous-archiving.html and
> noticed that wal_level isn't mentioned where I'd expect it to be.
> Specifically, there's a paragraph that starts, "To enable WAL archiving, set
> the archive_mode configuration parameter to on, and specify the shell command
> to use in the archive_command configuration parameter." There follows a long
> discussion of archive_command, but no further discussion of other
> configuration settings for several paragraphs, suggesting that those two
> configuration changes are the only ones required to end up with a useful
> archive. However, further on, it discusses wal_level:
>
>    "When wal_level is minimal some SQL commands are optimized to avoid WAL
>    logging, as described in Section 14.4.7. If archiving or streaming
>    replication were turned on during execution of one of these statements,
>    WAL would not contain enough information for archive recovery."
>
> ISTM wal_archive should make an appearance where the docs bring up
> archive_mode and archive_command, to say "wal_level must be set to 'archive'
> or 'hot_standby'", so all required configuration changes are mentioned close
> together.

Some descriptions about wal_level were added after beta1 release.
http://archives.postgresql.org/pgsql-committers/2010-05/msg00019.php

You can read the latest (development) document from
http://developer.postgresql.org/pgdocs/postgres/continuous-archiving.html

Regards,

--
Fujii Masao
NIPPON TELEGRAPH AND TELEPHONE CORPORATION
NTT Open Source Software Center