Hi,
Are you talking about checking for files in the pg_commit_ts directory of the old cluster?
 
The possibility of copying the catalog is checked here:
+    /*
+     * Copy old commit_timestamp data to new, if available.
+     */
+    is_copy_commit_ts =
+        (old_cluster.controldata.chkpnt_oldstCommitTsxid > 0 &&
+         old_cluster.controldata.chkpnt_newstCommitTsxid > 0 &&
+         user_opts.do_copy_pg_commit_ts);
+
+    if (is_copy_commit_ts)
+    {
+        copy_subdir_files("pg_commit_ts", "pg_commit_ts");
+        oldest_xid = old_cluster.controldata.chkpnt_oldstCommitTsxid;
+        newest_xid = old_cluster.controldata.chkpnt_newstCommitTsxid;
+    }
+    else
+        oldest_xid = newest_xid = old_cluster.controldata.chkpnt_nxtxid;
+
 
Do I need to check something else additionally in the old cluster before copying the pg_commit_ts directory?
 
----------------
Кому: 'ls7777' (ls7777@yandex.ru);
Копия: pgsql-hackers@postgresql.org, orlovmg@gmail.com, amit.kapila16@gmail.com, Masahiko Sawada (sawada.mshk@gmail.com);
Тема: Patch for migration of the pg_commit_ts directory;
01.06.2026, 06:25, "Hayato Kuroda (Fujitsu)" <kuroda.hayato@fujitsu.com>:

Dear Sergey,
 

 During copying, the copy_subdir_files function cleans up the target
 directory with the remove_new_subdir(new_subdir, true) function.


Correct, the function can discard existing directory. But my point was that how
do we ENSURE it's OK to remove.

Best regards,
Hayato Kuroda
FUJITSU LIMITED