On Mon, 2005-05-09 at 15:18 -0400, Tom Lane wrote: > Simon Riggs <simon@xxxxxxxxxxxxxxx> 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). Thats part of deadlock detection? I had thought we just blew one away... Thanks, Best Regards, Simon Riggs
