If auto_commit is On, a database COMMIT is performed after each successful statement.
By default, a COMMIT or ROLLBACK is performed only when the user issues a COMMIT or ROLLBACK statement or a SQL statement
that causes an automatic commit (such as the CREATE TABLE statement).
Note
By default, ODBC operates in autocommit mode. Even if you have set the auto_commit option to Off in Interactive SQL, the ODBC
setting overrides the Interactive SQL setting. You can change ODBC's setting using the SQL_ATTR_AUTOCOMMIT connection attribute.
ODBC autocommit is independent of the chained option.