David Rowley <dgrowle...@gmail.com> writes: > Right now we start 1 backend for each test in a parallel group then > wait for the final backend to complete before running the next group.
> Is a particular reason for it to work that way? There are a whole lot of cases where test Y depends on an earlier test X. Some of those dependencies are annotated in parallel_schedule, but I fear most are not. If we had a full list of such dependencies then we could imagine building a job scheduler that would dispatch any script that has no remaining dependencies. The cases where "script X can't run concurrently with script Y" are also problematic. It's not as easy to discover those through testing, since it might happen to work depending on timing. regards, tom lane