Re: Patch for migration of the pg_commit_ts directory

<div>Hi,</div><div> </div><div><div>At the time check_control_data is launched for the new cluster, the control file does not contain information about the set track_commit_timestamp=on. It is installed only in postgresql.conf. The check_track_commit_timestamp_parameter function is only needed for the new cluster. And you can not run it for the old cluster, but use data from the old_cluster.controldata.chkpnt_newstCommitTsxid control file. But this will be less clear than using the check_track_commit_timestamp_parameter function.</div><div> </div><div>The test can be shortened.</div></div><div> </div><div>----------------</div><div>Кому: 'ls7777' (ls7777@yandex.ru), orlovmg@gmail.com (orlovmg@gmail.com), amit.kapila16@gmail.com (amit.kapila16@gmail.com);</div><div>Копия: pgsql-hackers@postgresql.org;</div><div>Тема: Patch for migration of the pg_commit_ts directory;</div><div>07.10.2025, 08:15, "Hayato Kuroda (Fujitsu)" &lt;kuroda.hayato@fujitsu.com&gt;:</div><blockquote><p>Hi,<br /><br />Thanks for updating the patch.<br /><br />Regarding the check_track_commit_timestamp_parameter(), I'm not sure the function<br />is needed. Since pg_controldata outputs whether the commit_ts module is enabled<br />or not [1], can we obtain there instead?<br />I imagined like we can add a new field at ControlData, it could be obtained in get_control_data(),<br />values for instances could be compared in check_control_data().<br /><br />Another possibility is that oldestCommitTsXid/newestCommitTsXid can be always<br />valid if track_commit_timestamp is on. In this case the attribute is not needed<br />anymore. It is enough to check these values. Can you check them?<br /><br />Regarding the test, I feel it is unnecessary long. I feel it is enough to ensure<br />one or two transactions have the same timestamp on the both nodes, pgbench is not<br />needed. Current test may not be able to finish on the slow machine.<br /><br />[1]<br />```<br />$ pg_controldata data/ | grep "track_"<br />track_commit_timestamp setting: off<br />```<br /><br />Best regards,<br />Hayato Kuroda<br />FUJITSU LIMITED<br /> </p></blockquote>