Alvaro Herrera <alvhe...@commandprompt.com> writes: > Excerpts from Tom Lane's message of sáb ene 28 01:35:33 -0300 2012: >> This is the same thing I was complaining about in the bug #6123 thread, >> http://archives.postgresql.org/message-id/9698.1327266...@sss.pgh.pa.us
> Hm. Okay, I hadn't read that. > In my FOR KEY SHARE patch I have added a heap_lock_updated_tuple that > makes heap_lock_tuple follow the update chain forward when the tuple > being locked is being updated by a concurrent transaction. Um, we do that already, no? Certainly in READ COMMITTED queries, we will do so, though it happens at a higher level than heap_lock_tuple. > I haven't traced through FETCH to see if it makes sense to apply some > of that to it. The issue here is what to do when the update came from our *own* transaction. In particular I'm a bit worried about avoiding what the code calls the Halloween problem, namely an infinite loop of re-updating the same tuple if the scan keeps coming across newer versions. regards, tom lane -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers