On Mon, Mar 12, 2018 at 12:18 AM, Alexander Korotkov <a.korot...@postgrespro.ru> wrote: > On Sat, Mar 3, 2018 at 2:53 PM, Amit Kapila <amit.kapil...@gmail.com> wrote: >> >> On Fri, Mar 2, 2018 at 9:27 AM, Thomas Munro >> > If that is indeed a race, could it be fixed by >> > calling PredicateLockPageSplit() at the start of _hash_splitbucket() >> > instead? >> > >> >> Yes, but I think it would be better if we call this once we are sure >> that at least one tuple from the old bucket has been transferred >> (consider if all tuples in the old bucket are dead). > > > Is it really fair? For example, predicate lock can be held by session > which queried some key, but didn't find any corresponding tuple. > If we imagine this key should be in new bucket while all existing > tuples would be left in old bucket. As I get, in this case no locks > would be transferred since no tuples were moved to the new bucket. > So, further insertion to the new bucket wouldn't conflict with session, > which looked for non-existing key, while it should. Do it make sense? >
Valid point, I think on split we should always transfer locks from old bucket to new bucket. -- With Regards, Amit Kapila. EnterpriseDB: http://www.enterprisedb.com
