Good afternoon!

During pg_upgrade migration, the pg_commit_ts directory is not copied when track_commit_timestamp = on is set. There is a patch in the attachment that fixes this.

Contents & Purpose

==================

The patch copies the pg_commit_ts directory of the old cluster and updates the Latest checkpoints oldestCommitTsXid and Latest checkpoint's newestCommitTsXid for the new cluster. If required.

Initial Run

===========

The patch can be applied on the master branch.

I don't understand what tests are needed for such a patch. The patch is very simple.

Performance

===========

The pg_upgrade operation time increases by the time the pg_commit_ts catalog is copied.