Horton

Re: patch to allow disable of WAL recycling

Thomas Munro <thomas.munro@gmail.com>

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From: Thomas Munro <thomas.munro@gmail.com>
To: Jerry Jelinek <jerry.jelinek@joyent.com>
Cc: Robert Haas <robertmhaas@gmail.com>, Alvaro Herrera <alvherre@2ndquadrant.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: 2019-04-02T01:48:01Z
Lists: pgsql-hackers 
On Sat, Mar 30, 2019 at 11:18 AM Jerry Jelinek <jerry.jelinek@joyent.com> wrote:
> I went through your new version of the patch and it all looks great to me.

I moved the error handling logic around a bit so we'd capture errno
immediately after the syscalls.  I also made a couple of further
tweaks to comments and removed some unnecessary casts.

I suspect we took so long on this because of lack of ZFS knowledge and
uncertainty about the precise reason for the current coding in terms
of crash safety in general.  After learning more, I now suspect the
claim about fsyncdata(2) and indirect blocks in the comments may be
incorrect (it may stem from buggy behaviour on older Linux kernels),
but I'm not sure and it's not this patch's job to change that.

Pushed.  Thanks for the patch!

-- 
Thomas Munro
https://enterprisedb.com

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.