Hi Robert, Amit, thanks for working on this.
On 2016-06-09 12:11:15 -0400, Robert Haas wrote: > 4. The tests as written were not safe under concurrency; they could > return spurious results if the page changed between the time you > checked the visibility map and the time you actually examined the > tuples. I think people will try running these functions on live > systems, so I changed the code to recheck the VM bits after locking > the page. Unfortunately, there's either still a concurrency-related > problem here or there's a bug in the all-frozen code itself because I > once managed to get pg_check_frozen('pgbench_accounts') to return a > TID while pgbench was running concurrently. That's a bit alarming, > but since I can't reproduce it I don't really have a clue how to track > down the problem. Ugh, that's a bit concerning. > If there are not objections, I will go ahead and commit this tomorrow, > because even if there is a bug (see point #4 above) I think it's > better to have this in the tree than not. However, code review and/or > testing with these new functions seems like it would be an extremely > good idea. I'll try to spend some time on that today (code review & testing). Andres -- Sent via pgsql-hackers mailing list (firstname.lastname@example.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers