On Thu, May 29, 2014 at 6:43 PM, Claudio Freire <[email protected]> wrote: > On Thu, May 29, 2014 at 6:19 PM, Tom Lane <[email protected]> wrote: >> Claudio Freire <[email protected]> writes: >>> Didn't fix that, but the attached patch does fix regression tests when >>> scanning over index types other than btree (was invoking elog when the >>> index am didn't have ampeeknexttuple) >> >> "ampeeknexttuple"? That's a bit scary. It would certainly be unsafe >> for non-MVCC snapshots (read about vacuum vs indexscan interlocks in >> nbtree/README). > > > It's not really the tuple, just the tid
And, furthermore, it's used only to do prefetching, so even if the tid was invalid when the tuple needs to be accessed, it wouldn't matter, because the indexam wouldn't use the result of ampeeknexttuple to do anything at that time. Though, your comment does illustrate the need to document that on ampeeknexttuple, for future users. -- Sent via pgsql-hackers mailing list ([email protected]) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
