Re: Add an optional timeout clause to isolationtester step.

Julien Rouhaud <rjuju123@gmail.com> writes:
> On Sat, Mar 07, 2020 at 04:09:31PM -0500, Tom Lane wrote:
>> Julien Rouhaud <rjuju123@gmail.com> writes:
>>> On Sat, Mar 07, 2020 at 10:46:34AM -0500, Tom Lane wrote:
>>>> What's the actual need that you're trying to deal with?

>>> Testing the correct behavior of non trivial commands, such as CIC/reindex
>>> concurrently, that fails during the execution.

>> Hmm ... don't see how a timeout helps with that?

> For reindex concurrently, a SELECT FOR UPDATE on a different connection can
> ensure that the reindex will be stuck at some point, so canceling the command
> after a long enough timeout reproduces the original faulty behavior.

Hmm, seems like a pretty arbitrary (and slow) way to test that.  I'd
envision testing that by setting up a case with an expression index
where the expression is designed to fail at some point partway through
the build -- say, with a divide-by-zero triggered by one of the tuples
to be indexed.

            regards, tom lane