Horton

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

Dilip Kumar <dilipbalaut@gmail.com>

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From: Dilip Kumar <dilipbalaut@gmail.com>
To: Andres Freund <andres@anarazel.de>
Cc: Robert Haas <robertmhaas@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: 2022-03-23T17:20:17Z
Lists: pgsql-hackers 
On Wed, Mar 23, 2022 at 10:37 PM Andres Freund <andres@anarazel.de> wrote:
>
> Hi,
>
> On 2022-03-23 22:29:40 +0530, Dilip Kumar wrote:
> > I could not see any reason for it to fail, and I could not reproduce
> > it either.  Is it possible to access the server log for this cfbot
> > failure?
>
> Yes, near the top, below the cpu / memory graphs, there's a file
> navigator. Should have all files ending with *.log or starting with
> regress_log_*.

Okay, I think I have found the reasoning for this failure, basically,
if we see the below logs then the second statement is failing with
foobar5 already exists and that is because some of the above test case
is conditionally generating the same name.  So the fix is to use a
different name.

2022-03-23 13:53:54.554 UTC [32647][client backend]
[020_createdb.pl][3/12:0] LOG:  statement: CREATE DATABASE foobar5
TEMPLATE template0 LOCALE_PROVIDER icu ICU_LOCALE 'en';
......
2022-03-23 13:53:55.374 UTC [32717][client backend]
[020_createdb.pl][3/46:0] LOG:  statement: CREATE DATABASE foobar5
STRATEGY file_copy TEMPLATE foobar2;
2022-03-23 13:53:55.390 UTC [32717][client backend]
[020_createdb.pl][3/46:0] ERROR:  database "foobar5" already exists

-- 
Regards,
Dilip Kumar
EnterpriseDB: http://www.enterprisedb.com

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.