Re: Streaming replication, and walsender during recovery

Josh Berkus <josh@agliodbs.com>

From: Josh Berkus <josh@agliodbs.com>
To: Simon Riggs <simon@2ndQuadrant.com>
Cc: Heikki Linnakangas <heikki.linnakangas@enterprisedb.com>, Tom Lane <tgl@sss.pgh.pa.us>, Fujii Masao <masao.fujii@gmail.com>, PostgreSQL-development <pgsql-hackers@postgresql.org>
Date: 2010-01-28T20:05:32Z
Lists: pgsql-hackers
Guys,

> Hmm, I'm sorry but that's bogus. Retaining so much WAL that we are
> strongly in danger of blowing disk space is not what I would call a
> safety feature. Since there is no way to control or restrain the number
> of files for certain, that approach seems fatally flawed. Reducing
> checkpoint_timeout is the opposite of what you would want to do for
> performance.

Which WAL are we talking about here?  There's 3 copies to worry about:

1) master WAL
2) the archive copy of WAL
3) slave WAL

--Josh Berkus