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

Dilip Kumar <dilipbalaut@gmail.com>

From: Dilip Kumar <dilipbalaut@gmail.com>

To: Robert Haas <robertmhaas@gmail.com>

Cc: Andres Freund <andres@anarazel.de>, Heikki Linnakangas <hlinnaka@iki.fi>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>

Date: 2021-10-05T08:06:56Z

Lists: pgsql-hackers

Attachments

v5-0001-Refactor-relmap-load-and-relmap-write-functions.patch (application/octet-stream) patch v5-0001
v5-0003-Refactor-index_copy_data.patch (application/octet-stream) patch v5-0003
v5-0004-Extend-bufmgr-interfaces.patch (application/octet-stream) patch v5-0004
v5-0005-New-interface-to-lock-relation-id.patch (application/octet-stream) patch v5-0005
v5-0002-Extend-relmap-interfaces.patch (application/octet-stream) patch v5-0002
v5-0006-WAL-logged-CREATE-DATABASE.patch (application/octet-stream) patch v5-0006
v5-0007-POC-WAL-LOG-CREATE-DATABASE-APPROACH-2.patch (application/octet-stream) patch v5-0007

On Mon, Oct 4, 2021 at 2:51 PM Dilip Kumar <dilipbalaut@gmail.com> wrote:

I have implemented the patch with approach2 as well, i.e. instead of
scanning the pg-class, we scan the directory.

IMHO, we have already discussed most of the advantages and
disadvantages of both approaches so I don't want to mention those
again. But I have noticed one more issue with the approach2,
basically, if we scan the directory then we don't have any way to
identify the relation-OID and that is required in order to acquire the
relation lock before copying it, right?

Patch details:
0001 to 0006 implements an approach1
0007 removes the code of pg_class scanning and adds the directory scan.


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

Commits

When using the WAL-logged CREATE DATABASE strategy, bulk extend.
- 3e63e8462f31 16.0 landed
- 576bb0fc9342 15.0 landed
Avoid using a fake relcache entry to own an SmgrRelation.
- 1b94f8f232f6 15.0 landed
- 76733b399c49 16.0 landed
Fix data-corruption hazard in WAL-logged CREATE DATABASE.
- 692df425b688 16.0 landed
- 811203d4aff5 15.0 landed
initdb: When running CREATE DATABASE, use STRATEGY = WAL_COPY.
- ad43a413c4f7 15.0 landed
Simplify a needlessly-complicated regular expression.
- c6863b858291 15.0 landed
In 020_createdb.pl, change order of command-line arguments.
- 3d067c53b26d 15.0 landed
Add new block-by-block strategy for CREATE DATABASE.
- 9c08aea6a309 15.0 landed
Fix replay of create database records on standby
- 49d9cfc68bf4 15.0 cited
Refactor code for reading and writing relation map files.
- 39f0c4bd670c 15.0 landed
Replace RelationOpenSmgr() with RelationGetSmgr().
- f10f0ae420ee 15.0 cited
Refactor the fsync queue for wider use.
- 3eb77eba5a51 12.0 cited