On 11 April 2018 at 03:42, Tom Lane <t...@sss.pgh.pa.us> wrote: > Alvaro Herrera <alvhe...@alvh.no-ip.org> writes: >> 2. Do we want to revert Andrew's test stabilization patch? If I >> understand correctly, the problem is the inverse of what was diagnosed: >> "any running transaction at the time of the test could prevent pages >> from being set as all-visible". That's correct, but the test doesn't >> depend on pages being all-visible -- quite the contrary, it depends on >> the pages NOT being all-visible (which is why the HeapFetches counts are >> all non-zero). Since the pages contain very few tuples, autovacuum >> should never process the tables anyway. > > I did not especially like the original test output, because even without > the bug at hand, it seemed to me the number of heap fetches might vary > depending on BLCKSZ. Given that the point of the test is just to check > partition pruning, seems like IOS vs regular indexscan isn't a critical > difference. I'd keep Andrew's change but fix the comment.
hmm, I don't feel strongly about reverting or not, but if [auto-]vacuum has not visited the table, then I don't see why BLCKSZ would have an effect here. -- David Rowley http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Training & Services
