Horton

Re: Online enabling of checksums

Sergei Kornilov <sk@zsrv.org>

View thread View on postgr.es
From: Sergei Kornilov <sk@zsrv.org>
To: Magnus Hagander <magnus@hagander.net>, Andres Freund <andres@anarazel.de>
Cc: Andrey Borodin <x4mmm@yandex-team.ru>, Tomas Vondra <tomas.vondra@2ndquadrant.com>, Heikki Linnakangas <hlinnaka@iki.fi>, Daniel Gustafsson <daniel@yesql.se>, Michael Banck <michael.banck@credativ.de>, Robert Haas <robertmhaas@gmail.com>, Greg Stark <stark@mit.edu>, PostgreSQL-development <pgsql-hackers@postgresql.org>
Date: 2018-06-26T13:21:17Z
Lists: pgsql-hackers 
Hello

I tried build this patch and got error during make docs
> postgres.sgml:19626: element xref: validity error : IDREF attribute linkend references an unknown ID "runtime-checksumhelper-cost-limit"
> postgres.sgml:19625: element xref: validity error : IDREF attribute linkend references an unknown ID "runtime-checksumhelper-cost-delay"

Both new GUC checksumhelper_cost_delay and checksumhelper_cost_limit mentioned in postgresql.conf with special value -1 (-1 to use vacuum_cost_limit), but this value was not mentioned in docs. I noticed that the code and documentation describe different defaults.
Also i found one "<literal>in progress</literal>" in pg_enable_data_checksums() description. In other places status is called "inprogress" (without space).

>	VacuumPageHit = 0;
>	VacuumPageMiss = 0;
>	VacuumPageDirty = 0;
Hm, why these settings are set to 0 in checksumhelper process?

> /*
> * Force a checkpoint to get everything out to disk. XXX: this should
> * probably not be an IMMEDIATE checkpoint, but leave it there for now for
> * testing
> */
> RequestCheckpoint(CHECKPOINT_FORCE | CHECKPOINT_WAIT | CHECKPOINT_IMMEDIATE);
We need not forget that.

regards, Sergei

Commits

  1. Online enabling and disabling of data checksums

  2. Deactive flapping checksum isolation tests.

  3. Add support for coordinating record typmods among parallel workers.