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

Dilip Kumar <dilipbalaut@gmail.com>

From: Dilip Kumar <dilipbalaut@gmail.com>

To: Ashutosh Sharma <ashu.coek88@gmail.com>

Cc: Maciek Sakrejda <m.sakrejda@gmail.com>, Robert Haas <robertmhaas@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: 2022-03-03T16:22:37Z

Lists: pgsql-hackers

Attachments

v10-0002-Extend-relmap-interfaces.patch (text/x-patch) patch v10-0002
v10-0001-Refactor-relmap-load-and-relmap-write-functions.patch (text/x-patch) patch v10-0001
v10-0003-Refactor-index_copy_data.patch (text/x-patch) patch v10-0003
v10-0004-Extend-bufmgr-interfaces.patch (text/x-patch) patch v10-0004
v10-0005-New-interface-to-lock-relation-id.patch (text/x-patch) patch v10-0005
v10-0006-WAL-logged-CREATE-DATABASE.patch (text/x-patch) patch v10-0006

On Tue, Mar 1, 2022 at 5:15 PM Dilip Kumar <dilipbalaut@gmail.com> wrote:

> On Tue, Feb 22, 2022 at 8:27 PM Ashutosh Sharma <ashu.coek88@gmail.com>
> wrote:
>
>> I'm not sure about the current status, but found it while playing
>> around with the latest changes a bit, so thought of sharing it here.
>>
>> +      <varlistentry>
>> +       <term><replaceable class="parameter">strategy</replaceable></term>
>> +       <listitem>
>> +        <para>
>> +         This is used for copying the database directory.  Currently, we
>> have
>> +         two strategies the <literal>WAL_LOG_BLOCK</literal> and the
>>
>> Isn't it wal_log instead of wal_log_block?
>>
>> I think when users input wrong strategy with createdb command, we
>> should provide a hint message showing allowed values for strategy
>> types along with an error message. This will be helpful for the users.
>>
>
> I will fix these two comments while posting the next version.
>
>

The new version of the patch fixes these 2 comments pointed by Ashutosh and
also splits the GetRelListFromPage() function as suggested by Robert and
uses the latest snapshot for scanning the pg_class instead of active
snapshot as pointed out by Robert.  I haven't yet added the test case to
create a database using this new strategy option.  So if we are okay with
these two options FILE_COPY and WAL_LOG then I will add test cases for the
same.

-- 
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