Re: XLog size reductions: Reduced XLog record header size for PG17

Matthias van de Meent <boekewurm+postgres@gmail.com>

From: Matthias van de Meent <boekewurm+postgres@gmail.com>

To:

Cc: PostgreSQL Hackers <pgsql-hackers@postgresql.org>, Heikki Linnakangas <hlinnaka@iki.fi>, Robert Haas <robertmhaas@gmail.com>, Dilip Kumar <dilipbalaut@gmail.com>, Andres Freund <andres@anarazel.de>

Date: 2023-09-19T10:07:07Z

Lists: pgsql-hackers

Attachments

v5-0003-Rename-rmgr_identify-info-bits-argument-to-rmgrin.patch (application/octet-stream) patch v5-0003
v5-0004-Move-rmgr-info-bits-into-their-own-field-in-the-x.patch (application/octet-stream) patch v5-0004
v5-0002-Replace-accesses-to-rmgr-s-XLogRecord-info-bit-ac.patch (application/octet-stream) patch v5-0002
v5-0001-Reduce-overhead-of-small-block-data-in-xlog-recor.patch (application/octet-stream) patch v5-0001
v5-0005-Stop-the-logging-of-XIDs-in-records-where-the-XID.patch (application/octet-stream) patch v5-0005
v5-0006-Add-RM_INVALID-an-invalid-resource-manager.patch (application/octet-stream) patch v5-0006
v5-0007-Reformat-the-XLog-record-header.patch (application/octet-stream) patch v5-0007

On Wed, 12 Jul 2023 at 14:50, Matthias van de Meent
<boekewurm+postgres@gmail.com> wrote:
>
> On Mon, 3 Jul 2023 at 13:08, Matthias van de Meent
> <boekewurm+postgres@gmail.com> wrote:
> >
> > On Fri, 30 Jun 2023 at 17:36, Matthias van de Meent
> > <boekewurm+postgres@gmail.com> wrote:
> > >
> > > Hi,
> > >
> > > The attached v2 patchset contains some small fixes for the failing
> > > cfbot 32-bit tests - at least locally it does so.
> > >
> > > I'd overlooked one remaining use of MAXALIGN64() in xlog.c in the last
> > > patch of the set, which has now been updated to XLP_ALIGN as well.
> > > Additionally, XLP_ALIGN has been updated to use TYPEALIGN64 instead of
> > > TYPEALIGN so that we don't lose bits of the aligned value in 32-bit
> > > systems.
> >
> > Apparently there was some usage of MAXALIGN() in xlogreader that I'd
> > missed, and which only shows up in TAP tests. In v3 I've fixed that,
> > together with some improved early detection of invalid record headers.
>
> Another fix for CFBot - pg_waldump tests which were added in 96063e28
> exposed an issue in my patchset related to RM_INVALID_ID.
>
> v4 splits former patch 0006 into two: now 0006 adds RM_INVALID and
> does the rmgr-related changes in the code, and 0007 does the WAL disk
> format overhaul.

V5 is a rebased version of v4, and includes the latest patch from
"smaller XLRec block header" [0] as 0001.

Kind regards,

Matthias van de Meent

[0] https://www.postgresql.org/message-id/CAEze2WhG_qvs0_HPCKyGLjFSSeiLZJcFhT%3DrzEUd7AzyxnSfKw%40mail.gmail.com