An XDB Server database is a collection of tables, indexes and table spaces. Each database definition occupies a separate directory. A database consists of a number of files that may span several directories and disks if stogroups are used. Database names are stored in the system table SYSIBM.SYSDATABASE. A database is created using the CREATE DATABASE statement. Every location contains a default database (DSNDB04) and a system catalog database (DSNDB06). In addition a location may include a number of user-defined databases. The SYSTEM location includes two additional databases: XDBACF (stores information on security and access) and DSNDDF (stores information on other locations.)