Horton

Re: Latch for the WAL writer - further reducing idle wake-ups.

Tom Lane <tgl@sss.pgh.pa.us>

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From: Tom Lane <tgl@sss.pgh.pa.us>
To: Robert Haas <robertmhaas@gmail.com>
Cc: Peter Geoghegan <peter@2ndquadrant.com>, PG Hackers <pgsql-hackers@postgresql.org>
Date: 2012-05-03T03:42:40Z
Lists: pgsql-hackers

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →

  1. Make bgwriter sleep longer when it has no work to do, to save electricity.

Robert Haas <robertmhaas@gmail.com> writes:
> ... It seems unlikely to cause any real
> problem if WAL writer takes a couple seconds to get with the program
> after a long period of inactivity; note that an async commit will kick
> it anyway, and a sync commit will probably half to flush WAL whether
> the WAL writer wakes up or not.

That's a good point.  What about only kicking the WAL writer in code
paths where a backend found itself having to write/flush WAL for itself?
The added overhead is very surely negligible in such a situation.

			regards, tom lane