From: | Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> |
---|---|
To: | Andres Freund <andres(at)2ndquadrant(dot)com> |
Cc: | Robert Haas <robertmhaas(at)gmail(dot)com>, Josh Berkus <josh(at)agliodbs(dot)com>, Bruce Momjian <bruce(at)momjian(dot)us>, Heikki Linnakangas <hlinnakangas(at)vmware(dot)com>, Peter Geoghegan <pg(at)heroku(dot)com>, Claudio Freire <klaussfreire(at)gmail(dot)com>, "David E(dot) Wheeler" <david(at)justatheory(dot)com>, "pgsql-hackers(at)postgresql(dot)org" <pgsql-hackers(at)postgresql(dot)org>, Andrew Dunstan <andrew(at)dunslane(dot)net>, Jan Wieck <jan(at)wi3ck(dot)info> |
Subject: | Re: open items for 9.4 |
Date: | 2014-09-29 20:35:12 |
Message-ID: | 11026.1412022912@sss.pgh.pa.us |
Views: | Raw Message | Whole Thread | Download mbox | Resend email |
Thread: | |
Lists: | pgsql-hackers |
Andres Freund <andres(at)2ndquadrant(dot)com> writes:
> On 2014-09-29 16:16:38 -0400, Tom Lane wrote:
>> I wonder why it's a fixed constant at all, and not something like
>> "wal_buffers / 8".
> Because that'd be horrible performancewise on a system with many
> wal_buffers. There's several operations where all locks are checked in
> sequence (to see whether there's any stragglers that need to finish
> inserting) and even some where they're acquired concurrently (e.g. for
> xlog switch, checkpoint and such).
Hm. Well, if there are countervailing considerations as to how large is a
good value, that makes it even less likely that it's sensible to expose
it as a user tunable. A relevant analogy is that we don't expose a way
to adjust the number of lock table partitions at runtime.
regards, tom lane
From | Date | Subject | |
---|---|---|---|
Next Message | Andrew Dunstan | 2014-09-29 20:38:57 | Re: json (b) and null fields |
Previous Message | Tom Lane | 2014-09-29 20:32:36 | Re: json (b) and null fields |