Horton

Re: Offline enabling/disabling of data checksums

Bernd Helmle <mailings@oopsware.de>

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From: Bernd Helmle <mailings@oopsware.de>
To: Fabien COELHO <coelho@cri.ensmp.fr>
Cc: Michael Banck <michael.banck@credativ.de>, Magnus Hagander <magnus@hagander.net>, Michael Paquier <michael@paquier.xyz>, Postgres hackers <pgsql-hackers@postgresql.org>
Date: 2019-01-08T15:41:35Z
Lists: pgsql-hackers 
Am Dienstag, den 08.01.2019, 16:17 +0100 schrieb Fabien COELHO:
> > > Adding a new state to ControlFileData which would prevent it from
> > > starting?
> > 
> > But then you have to make sure the control flag gets cleared in any
> > case pg_verify_checksums crashes somehow or gets SIGKILL'ed ...
> 
> The usual approach is a restart with some --force option?
> 
> > Setting the checksum flag is done after having finished all blocks,
> > so
> > there is no problem.
> 
> There is also a problem if the db is started while the checksum is
> being 
> enabled.

What i mean is that interrupting pg_verify_checksums won't leave
pg_control in a state where starting the cluster won't work without any
further interaction.

Bernd.

Commits

  1. Reorganize Notes section in documentation of pg_checksums

  2. Add option -N/--no-sync to pg_checksums

  3. Add options to enable and disable checksums in pg_checksums

  4. Refactor more code logic to update the control file

  5. Rename pg_verify_checksums to pg_checksums

  6. Fix cross-version compatibility checks of pg_verify_checksums

  7. Add routine able to update the control file to src/common/