The distinction between master and personal data base (DB and PDB respectively) is both operational and philosophical. This distinction is a basic concept for the use of DIRA2.
The Master DB level is created by the Data Base Administrator of a site and can be used by all users in read-only mode. The output of this query will produce one or more files that can reside in the Personal Data Base area, so the user can access them in read/write mode.
The personal data base is a complete subsystem used and managed by a single user. DIRA2 system files are written in the user current directory at the time of creation of a PDB. In the Personal Data Base the user can insert his own catalogues, coming from previous selection, copied from other astronomical centers or created with a editor. A user can create more PDBs in separate directories, but he can access them one at a time. Instead he can mix the access to the Master DB and Personal DB in most of the DIRA2 commands.