Horton

Re: patch to allow disable of WAL recycling

Robert Haas <robertmhaas@gmail.com>

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From: Robert Haas <robertmhaas@gmail.com>
To: Alvaro Herrera <alvherre@2ndquadrant.com>
Cc: Jerry Jelinek <jerry.jelinek@joyent.com>, Michael Paquier <michael@paquier.xyz>, Peter Eisentraut <peter.eisentraut@2ndquadrant.com>, Tomas Vondra <tomas.vondra@2ndquadrant.com>, Thomas Munro <thomas.munro@enterprisedb.com>, Andres Freund <andres@anarazel.de>, Pg Hackers <pgsql-hackers@postgresql.org>
Date: 2019-03-06T15:38:13Z
Lists: pgsql-hackers 
On Wed, Feb 27, 2019 at 6:12 PM Alvaro Herrera <alvherre@2ndquadrant.com> wrote:
> I think the idea of it being a generic tunable for assorted behavior
> changes, rather than specific to WAL recycling, is a good one.  I'm
> unsure about your proposed name -- maybe "wal_cow_filesystem" is better?

I *really* dislike this.  For one thing, it means that users don't
have control over the behaviors individually.  For another, the
documentation is now quite imprecise about what the option actually
does, while expecting users to figure out whether those behaviors are
acceptable or preferable in their environment.  It lists recycling of
WAL files and zero-filling of those files as examples of behavior
changes, but it does not say that those are the only changes, or even
that they are made in all cases.

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

Commits

  1. Add wal_recycle and wal_init_zero GUCs.

  2. Add GUC and storage parameter to set the maximum size of GIN pending list.