Horton

Re: shared memory based stat collector (was: Sharing record typmods between backends)

Robert Haas <robertmhaas@gmail.com>

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From: Robert Haas <robertmhaas@gmail.com>
To: Andres Freund <andres@anarazel.de>
Cc: Magnus Hagander <magnus@hagander.net>, Tom Lane <tgl@sss.pgh.pa.us>, Thomas Munro <thomas.munro@enterprisedb.com>, Dilip Kumar <dilipbalaut@gmail.com>, Pg Hackers <pgsql-hackers@postgresql.org>
Date: 2017-08-14T17:06:48Z
Lists: pgsql-hackers 
On Mon, Aug 14, 2017 at 1:02 PM, Andres Freund <andres@anarazel.de> wrote:
> I previously thought that an option to occasionally WAL log the stats
> file would be useful (e.g. just before a checkpoint). That'd make them
> persistent, and available on the standby. But that'd still require
> somehow dealing with stats being produced on the standby - I presume
> we'd need multiple stats files and provide functions for merging them.

Well, if you think the stats files might be too big to fit in memory,
then you're probably imagining tens of gigabytes of data, and you're
not going to want to write a WAL record that size, either.

-- 
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company

Commits

  1. Simplify autovacuum work-item implementation

  2. Fix error handling path in autovacuum launcher

  3. Dramatically reduce System V shared memory consumption.