If I stop a long running query, does it rollback?

Question

A query that is used to loop through 17 millions records to remove duplicates has been running now for about 16 hours and I wanted to know if the query is sto

Answer 1

If you don't do anything explicit about transactions then the connection will be in autocommit transactions mode. In this mode every SQL statement is considered a transaction.

The question is whether this means the individual SQL statements are transactions and are therefore being committed as you go, or whether the outer WHILE loop counts as a transaction.

There doesn't seem to be any discussion of this in the description of the WHILE construct on MSDN. However, since a WHILE statement can't directly modify the database it would seem logical that it doesn't start an auto-commit transaction.