Horton

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

Ashutosh Sharma <ashu.coek88@gmail.com>

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From: Ashutosh Sharma <ashu.coek88@gmail.com>
To: Robert Haas <robertmhaas@gmail.com>
Cc: Dilip Kumar <dilipbalaut@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: 2022-03-11T15:12:26Z
Lists: pgsql-hackers 
On Fri, Mar 11, 2022 at 8:21 PM Robert Haas <robertmhaas@gmail.com> wrote:
>
> On Fri, Mar 11, 2022 at 12:15 AM Ashutosh Sharma <ashu.coek88@gmail.com> wrote:
> > Looks better, but why do you want to pass elevel to the
> > load_relmap_file()? Are we calling this function from somewhere other
> > than read_relmap_file()? If not, do we have any plans to call this
> > function  directly bypassing read_relmap_file for any upcoming patch?
>
> If it fails during CREATE DATABASE, it should be ERROR, not FATAL. In
> that case, we only need to stop trying to create a database; we don't
> need to terminate the session. On the other hand if we can't read our
> own database's relmap files, that's an unrecoverable error, because we
> will not be able to run any queries at all, so FATAL is appropriate.
>

OK. I can see it being used in the v13 patch. In the previous patches
it was hard-coded with FATAL. Also, we simply error out when doing
file copy as I can see in the copy_file function. So yes FATAL is not
the right option to use when creating a database. Thanks.

--
With Regards,
Ashutosh Sharma.

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.