Re: [Bizgres-general] WAL bypass for INSERT, UPDATE and
Tom Lane <tgl@sss.pgh.pa.us>
From: Tom Lane <tgl@sss.pgh.pa.us>
To: Hannu Krosing <hannu@skype.net>
Cc: Greg Stark <gsstark@mit.edu>, Qingqing Zhou <zhouqq@cs.toronto.edu>, pgsql-hackers@postgresql.org
Date: 2005-12-28T00:30:12Z
Lists: pgsql-hackers
Hannu Krosing <hannu@skype.net> writes: > making one of WAL files (strategies) be /dev/null would almost get us > non-logged writes, except for a little overhead in write() calls. > fsync() on /dev/null should be instantaneous . No, you really do want to push it up to a higher level than that. The CPU and contention costs of generating a WAL record are nontrivial, and doing so only to throw it away is pretty silly. What's more, pointing WAL at /dev/null would disable logging for the entire database cluster, not just selected tables which is what people seem to be asking for in this thread. (No, I don't wish to deal with multiple WAL output streams...) regards, tom lane