Horton

Re: Online enabling of checksums

x4mmm@yandex-team.ru

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From: Andrey Borodin <x4mmm@yandex-team.ru>
To: Daniel Gustafsson <daniel@yesql.se>
Cc: Michael Banck <michael.banck@credativ.de>, Magnus Hagander <magnus@hagander.net>, Tomas Vondra <tomas.vondra@2ndquadrant.com>, Robert Haas <robertmhaas@gmail.com>, Greg Stark <stark@mit.edu>, PostgreSQL-development <pgsql-hackers@postgresql.org>
Date: 2018-03-19T10:40:56Z
Lists: pgsql-hackers 
Hi, Daniel!

> 19 марта 2018 г., в 4:01, Daniel Gustafsson <daniel@yesql.se> написал(а):
> 
> Fixed in patch just posted in 84693D0C-772F-45C2-88A1-85B4983A5780@yesql.se
> (version 5). Thanks!


I've been hacking a bit in neighboring thread.
And come across one interesting thing. There was a patch on this CF on enabling checksums for SLRU. The thing is CLOG is not protected with checksums right now. But the bad thing about it is that there's no reserved place for checksums in SLRU.
And this conversion from page without checksum to page with checksum is quite impossible online.

If we commit online checksums before SLRU checksums, we will need very neat hacks if we decide to protect SLRU eventually.

What do you think about this problem?

Best regards, Andrey Borodin.

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.