| From: | Bruce Momjian <bruce(at)momjian(dot)us> |
|---|---|
| To: | PostgreSQL-development <pgsql-hackers(at)postgresql(dot)org> |
| Subject: | Default setting for autovacuum_freeze_max_age |
| Date: | 2016-10-21 13:19:34 |
| Message-ID: | 20161021131934.GA23502@momjian.us |
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| Lists: | pgsql-hackers |
Why is autovacuum_freeze_max_age's default set to 200 million, rather
than something like 2 billion? It seems 2 billion is half way to
wrap-around and would be a better default. Right now, the default seems
to freeze 10x more often than it has to.
Does it default to 200 million so clog can be trimmed? Is that
reasonable? We have tuple status flags of commit status so I assume
changing from a normal xid to a frozen one doesn't have a performance
benefit, does it?
--
Bruce Momjian <bruce(at)momjian(dot)us> http://momjian.us
EnterpriseDB http://enterprisedb.com
+ As you are, so once was I. As I am, so you will be. +
+ Ancient Roman grave inscription +
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