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: Heikki Linnakangas <hlinnaka@iki.fi>
Cc: Andres Freund <andres@anarazel.de>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Date: 2021-06-17T13:04:04Z
Lists: pgsql-hackers 
On Thu, Jun 17, 2021 at 2:50 PM Heikki Linnakangas <hlinnaka@iki.fi> wrote:
>
> On 17/06/2021 08:45, Dilip Kumar wrote:
> > Another problem with directly scanning the directory is, how we
> > are supposed to get the "relpersistence" which is stored in pg_class
> > tuple right?
>
> You only need relpersistence if you want to use the buffer cache, right?
> I think that's a good argument for not using it.

Yeah, that is the one place,  another place I am using it to decide
whether to WAL log the new page while writing into the target
relfilenode, if it is unlogged relation then I am not WAL logging. But
now, I think that is not the right idea, during creating the database
we should WAL log all the pages irrespective of whether the table is
logged or unlogged.

-- 
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.