If connected to an Online Server, Informix supports isolation levels 0 (read uncommitted), 1 (read committed), and 3 (serializable). The default is 1. The Standard Engine supports isolation level 0 (read uncommitted) only.Informix also supports an alternative isolation level 1, called "cursor stability." Your ODBC application can use this isolation level by calling SQLSetConnectAttr (1040,1).Additionally, if transaction logging has not been enabled for your database, then transactions are not supported by the driver (the driver is always in auto-commit mode).Refer to Chapter 7 “Locking and Isolation Levels” in the DataDirect Connect Series for ODBC Reference for details.