ingres_autocommit() is called before opening a
transaction (before the first call to
ingres_query() or just after a call to
ingres_rollback() or
ingres_commit()) to switch the
"autocommit" mode of the server on or off (when the script begins
the autocommit mode is off).
When the autocommit mode is on, every query is automatically
committed by the server, as if ingres_commit()
was called after every call to ingres_query().