On 10/17/2012 04:16 PM, Albe Laurenz wrote:
Why? They can be serialized. The outcome would be exactly the same if session 2 completed before session 1 began.
Hmm. Good point; so long as *either* ordering is valid it's fine, it's only when *both* orderings are invalid that a serialization failure would occur. For some reason I had myself thinking that if a conflict could occur in either ordering the tx would fail, which wouldn't really be desirable and isn't how it works.
BTW, the issue with the underlying question is that their "name" column is unique. They expected to get a serialization failure on duplicate insert into "name", not a unique constraint violation. The question wasn't "why doesn't this fail" but "Why does this fail with a different error than I expected". Not that the question made that particularly clear.
-- Craig Ringer -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
