Re: Clarification on the release notes of postgresql 12 regarding pg_upgrade

=?UTF-8?B?Sm9zZWYgxaBpbcOhbmVr?= <josef.simanek@gmail.com> writes:
> But the problem in this case is probably this note:
>> This means that a REINDEX
>> <https://www.postgresql.org/docs/12/sql-reindex.html> operation on an
>> index pg_upgrade'd from a previous release could potentially fail.

> You can't REINDEX safely regarding that note.

Actually running into that problem is quite unlikely; and if you did
hit it, it'd just mean that the REINDEX fails, not that you have any
urgent problem to fix.  I'd encourage you to just go ahead and REINDEX,
if you have indexes that could benefit from the other changes.

            regards, tom lane