[SOLVED] MARIADB hangs upon last table update

Nextcloud version: 15 (?)
Operating system and version: Debian 8 (Raspbian, in fact, on a RPi 3)
PHP version: 7.3

The issue I’m facing:
So, as to enable 4-byte support in MySQL, I followed the instructions on admin manual page.

I’m using MariaDB (10.0.38 IIRC), so I followed the corresponding steps.

I’m stuck at step four: The tables needs to be migrated to “Barracuda” manually, one by one. I copied the concat output, and pasted it back to the MySQL shell. All went well, with tables getting new file extensions:

ariaDB [(none)]> ALTER TABLE `nextcloud`.`oc_vcategory_to_object` ROW_FORMAT=DYNAMIC;
Query OK, 0 rows affected (0.04 sec)
Records: 0  Duplicates: 0  Warnings: 0

However, the process is now stuck at the very last table:

MariaDB [(none)]> ALTER TABLE `nextcloud`.`oc_whats_new` ROW_FORMAT=DYNAMIC;

There’s no indication of progress (as I’ve seen for some of the other tables) - nothing seems happening. I don’t know if I can abort the process, or if that would damage anything. Any help would be appreciated - can I cut the process & retry? For now I’ll just let my computer run in the hope not to damage anything.

EDIT: I just checked in a new shell, and everything is correct except for the last table:

| nextcloud/oc_vcategory_to_object      |   255 | Barracuda   |
| nextcloud/oc_whats_new                |   127 | Antelope    |
+---------------------------------------+-------+-------------+

Ok, I took a shot and aborted the MariaDB shell and retried - then the last table updated within the second. Weird.