Re: pg_upgrade check for invalid databases

> On 7 Oct 2024, at 22:04, Nathan Bossart <nathandbossart@gmail.com> wrote:
>
> On Mon, Oct 07, 2024 at 03:37:35PM -0400, Bruce Momjian wrote:
>> On Tue, Oct  1, 2024 at 09:28:54AM +0200, Daniel Gustafsson wrote:
>>> Correct, sorry for being unclear.  The consistency argument would be to expand
>>> pg_upgrade to report all invalid databases rather than just the first found;
>>> attempting to fix problems would be a new behavior.
>>
>> Yes, historically pg_upgrade will fail if it finds anything unusual,
>> mostly because what it does normally is already scary enough.  If users
>> what pg_upgrade to do cleanups, it would be enabled by a separate flag,
>> or even a new command-line app.
>
> While I suspect it's rare that someone CTRL-C's out of an accidental DROP
> DATABASE and then runs pg_upgrade before trying to recover the data, I
> agree with the principle of having pg_upgrade fail by default for things
> like this.  If we did add a new flag, the new invalid database report that
> Daniel mentions could say something like "try again with
> --skip-invalid-databases to have pg_upgrade automatically drop invalid
> databases."

If we are teaching pg_upgrade to handle errors, either by skipping or by
fixing, then I believe this is the right way to go about it.  A successful run
should probably also create a report of the databases which were skipped.

--
Daniel Gustafsson