On Jun 4, 2008, at 6:00 PM, Jeff Davis wrote:
Some other concurrent transaction could still
insert something after the UPDATE but before the INSERT, so the unique
constraint violation can still occur.
Yes, I saw the comment. I'm guessing I'm missing something wrt
transaction isolation level or locking. Would I need to use
SERIALIZABLE or some kind of locking? Is the function in the example
any different than the following explicit transaction (with the UPDATE
not affecting any rows)?
BEGIN;
UPDATE db SET b = data WHERE a = key;
INSERT INTO db(a,b) VALUES (key, data);
COMMIT;
I'm obviously on the cusp of learning something new, or understanding
concurrency more deeply, so I'm looking forward to your responses.
Cheers,
Michael Glaesemann
grzm seespotcode net
