Re: Lock ACCESS EXCLUSIVE and Select question !

On Tue, Mar 01, 2011 at 09:23:49AM -0500, Alan Acosta wrote:

> seats have an specific bus even 5 minutes before departure, sometimes i know
> sometimes i don't, even sometimes when i know i have to change on fly this
> capacity, for example my bus crash just before departure, so i have to use a
> default averaged capacity. A human must have the final word about which bus
> departure, so the software must be very very open to changes.

This still sounds a little odd to me, but there is another way to do
it, and someone suggested it in this thread. If you're doing this
only with INSERT, then you just need to find some combination of
columns that needs to be unique (one of which is obviously the seat
number). Then you'll get a unique violation when two people try to
insert the same data, and someone will lose.

Your application could catch this in a savepoint and try again with a
different seat number.

A

--
Andrew Sullivan
ajs(at)crankycanuck(dot)ca