Ray Herring (3/6/2009)
I agree with BitBucket. The results described at what you would expect in "normal" operations (assuming the typo is corrected)
I understand the sections BitBucket quoted, but can't see how the answer SNAPSHOT is correct and READ COMMITTED isn't when the scenario has no commits!
As far I can see, since nothing has been committed, it doesn't matter which isolation level is in effect, transaction 1 won't see any change.
Now if the scenario was changed so that transaction 2 committed it's change before 1's 2nd select then the described behaviour is SNAPSHOT isolation level. But the question explicitly stated
The first transaction continues and again executes before the 2nd transaction committs
In this situation, it's impossible to tell whether it's SNAPSHOT or READ COMMITTED, as my test scripts show!
Derek