Update from NC 12.0.1 to NC 12.0.2 fails with PGSQL database

Hello guys,

I tried this morning my first update of NextCloud, after migrating from OwnCloud.
Looks like I’m out of luck : it was not a success.

Here are some info on my instance
Hosting OS: Debian 9.1
Apache version: 2.4.25
PHP interpreter: v7.0.19
Backend: postgresql v9.6

The upgrade procedure fails with that error:
Doctrine\DBAL\Exception\DriverException: An exception occurred while executing ‘ALTER TABLE oc_jobs ALTER id TYPE SERIAL’:
SQLSTATE[42704]: Undefined object: 7 ERROR: type “serial” does not exist

After reading some doc on PG, it seems that the “serial” type is not available for update: it is mostly a shorthand to be used at table creation time to create a sequence, and use it to feed an auto-incrementing int column.

How can I read and analyze the DB upgrade script ?

Thanks for your help,