Re: [Bizgres-general] WAL bypass for INSERT, UPDATE and - Mailing list pgsql-hackers

From Tom Lane
Subject Re: [Bizgres-general] WAL bypass for INSERT, UPDATE and
Date
Msg-id 9450.1135729812@sss.pgh.pa.us
Whole thread Raw
In response to Re: [Bizgres-general] WAL bypass for INSERT, UPDATE and  (Hannu Krosing <hannu@skype.net>)
List 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


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