Horton

Re: [Proposal] Fully WAL logged CREATE DATABASE - No Checkpoints

Andres Freund <andres@anarazel.de>

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From: Andres Freund <andres@anarazel.de>
To: Robert Haas <robertmhaas@gmail.com>
Cc: Dilip Kumar <dilipbalaut@gmail.com>, Thomas Munro <thomas.munro@gmail.com>, Ashutosh Sharma <ashu.coek88@gmail.com>, Maciek Sakrejda <m.sakrejda@gmail.com>, Bruce Momjian <bruce@momjian.us>, Alvaro Herrera <alvherre@alvh.no-ip.org>, Andrew Dunstan <andrew@dunslane.net>, Heikki Linnakangas <hlinnaka@iki.fi>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Date: 2022-03-31T16:25:18Z
Lists: pgsql-hackers 
Hi,

On 2022-03-31 10:05:10 -0400, Robert Haas wrote:
> On Thu, Mar 31, 2022 at 3:52 AM Dilip Kumar <dilipbalaut@gmail.com> wrote:
> > 0001 is changing the strategy to file copy during initdb and 0002
> > patch adds the test cases for both these cases.
> 
> IMHO, 0001 looks fine, except for needing some adjustments to the wording.

Agreed.


> I'm less sure about 0002. It's testing the stuff Andres mentioned, but
> I'm not sure how good the tests are.

I came to a similar conclusion. It's still better than nothing, but it's just
a small bit of additional effort to do some basic testing that e.g. the move
actually worked...


> Andres, thoughts? Do you want me to polish and commit 0001?

Yes please!


FWIW, once the freeze is done I'm planning to set up scripting to see which
parts of the code we whacked around don't have test coverage...

Greetings,

Andres Freund

Commits

  1. When using the WAL-logged CREATE DATABASE strategy, bulk extend.

  2. Avoid using a fake relcache entry to own an SmgrRelation.

  3. Fix data-corruption hazard in WAL-logged CREATE DATABASE.

  4. initdb: When running CREATE DATABASE, use STRATEGY = WAL_COPY.

  5. Simplify a needlessly-complicated regular expression.

  6. In 020_createdb.pl, change order of command-line arguments.

  7. Add new block-by-block strategy for CREATE DATABASE.

  8. Fix replay of create database records on standby

  9. Refactor code for reading and writing relation map files.

  10. Replace RelationOpenSmgr() with RelationGetSmgr().

  11. Refactor the fsync queue for wider use.