This identifies the name of the default log file for transaction management. The default log file is opened at the beginning of the first transaction unless NO_LOG_FILE_OK is set to 1. If it does not exist, it is created. This variable can be set programmatically with the SET ENVIRONMENT verb. The default setting is empty. Unless you have set NO_LOG_FILE_OK to 1, you must set the LOG_FILE variable if you want to use transaction management.