The database server cannot create a temporary disk file. The file should be created in the directory specified by the DBTEMP environment variable. If DBTEMP is not defined, the database server searches by default in the root directory for a subdirectory named tmp in which to create the temporary disk file. Check the accompanying ISAM error code, and look for operating-system error messages that might give more information. Possibly your account does not have write permission in that directory, or the disk might be full. Since Version 5.01, IBM Informix SE database server uses the DBTEMP environment variable, but IBM Informix Dynamic Server and IBM Informix OnLine Dynamic Server do not.