On Fri, Nov 11, 2005 at 06:00:32PM -0500, Rod Taylor wrote: > So? That is what save points are for. You can even skip the select for > update if you don't mind dead tuples from the attempted insert. > SELECT ... FOR UPDATE; > IF not exists THEN > SAVEPOINT; > INSERT ; > IF UNIQUE VIOLATION THEN > /* Someone else inserted between the SELECT and our INSERT */ > ROLLBACK TO SAVEPOINT; > UPDATE; > ELSE > RELEASE SAVEPOINT; > FI > ELSE > UPDATE; > FI
Isn't there still a race between INSERT and UPDATE? Low probability, for sure, as it would have had to not exist, then exist, then not exist, but still possible. I'd like a REPLACE that could be safe, or at least cause a COMMIT to fail, for this reason. Cheers, mark -- [EMAIL PROTECTED] / [EMAIL PROTECTED] / [EMAIL PROTECTED] __________________________ . . _ ._ . . .__ . . ._. .__ . . . .__ | Neighbourhood Coder |\/| |_| |_| |/ |_ |\/| | |_ | |/ |_ | | | | | | \ | \ |__ . | | .|. |__ |__ | \ |__ | Ottawa, Ontario, Canada One ring to rule them all, one ring to find them, one ring to bring them all and in the darkness bind them... http://mark.mielke.cc/ ---------------------------(end of broadcast)--------------------------- TIP 2: Don't 'kill -9' the postmaster