Transactions complete with one of the following events:
A COMMIT statement makes the changes to the database permanent.
A ROLLBACK statement undoes all the changes made by the transaction.
A disconnection from a database causes an implicit rollback (the default) or commit, depending on whether the DBISQL option COMMIT_ON_EXIT is set.
A statement with a side effect of an automatic commit is executed.
Database definition commands, such as ALTER, CREATE, and DROP all have the side effect of an automatic commit. You can also use two DBISQL options to cause a commit to occur automatically.
