Simon Riggs <simon@2ndquadrant.com> writes:
> On Mon, 2005-05-09 at 12:21 -0500, Kris Kiger wrote:
>> Quick question. I lock a table, call it table X, and then issue two
>> updates on that table. The two updates are left waiting. I then unlock
>> the table. The two updates go through. My question is, is there a
>> predictable way to determine which query will be executed first?
> The lock queue is served in FIFO sequence.
... usually. We will promote later arrivals in front of older ones if
the alternative would be a deadlock (eg, the later one already holds
some lock that would block the earlier one).
regards, tom lane