Re: reindex concurrently and two toast indexes

On Wed, Mar 04, 2020 at 09:21:45AM +0100, Julien Rouhaud wrote:
> Thanks for the patch!  I started to look at it during the weekend, but
> I got interrupted and unfortunately didn't had time to look at it
> since.

No problem, thanks for looking at it.  I have looked at it again this
morning, and applied it.

> The fix looks good to me.  I also tried multiple failure scenario and
> it's unsurprisingly working just fine.  Should we add some regression
> tests for that?  I guess most of it could be borrowed from the patch
> to fix the toast index issue I sent last week.

I have doubts when it comes to use a strategy based on
pg_cancel_backend() and a match of application_name (see for example
5ad72ce but I cannot find the associated thread).  I think that we
could design something more robust here and usable by all tests, with
two things coming into my mind: 
- A new meta-command for isolation tests to be able to cancel a
session with PQcancel().
- Fault injection in the backend.
For the case of this thread, the cancellation command would be a better
match.
--
Michael