On Fri, Oct 21, 2016 at 10:44:41AM -0400, Tom Lane wrote: > Bruce Momjian <br...@momjian.us> writes: > > 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. > > Please see the archives. I do not remember the reasoning, but there > was some, and you need to justify why it was wrong not just assert > that you think it's silly.
I think the reasoning was to avoid checking old clog files, but with tuple transaction status bits, e.g. HEAP_XMIN_COMMITTED, which were added long ago, I don't remember why either. I remember asking years ago and not getting a good answer, and giving up. If no one can give an answer, I suggest we change the default. -- Bruce Momjian <br...@momjian.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 + -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
