iX V6.5 (30391-90011)

50 Chapter2

Database Structure and Protection

Protecting the Database

TurboIMAGE/XL prevents unauthorized persons from gaining access to the database. It

provides external protection through the MPE/iX privileged ﬁle, account, and group

constructs and, in addition, provides the database designer and database manager with

methods to reﬁne security within the database.

Privileged File Protection

All TurboIMAGE/XL database ﬁles are privileged ﬁles. (Refer to the MPE/iX Intrinsics

Reference Manual for a description of the MPE/iX privileged ﬁle capability.) Access by

unprivileged processes or through most MPE/iX ﬁle system commands is not allowed.

Therefore, non-privileged users are prevented from accidentally or deliberately gaining

access to the database.

Using MPE/iX commands that permit copying TurboIMAGE/XL ﬁles to tape represents a

potential breach of database privacy, and their use should be controlled. In particular,

anyone who uses the MPE/iX SYSGEN, STORE, or RESTORE commands should notify the

database manager. The SYSGEN and STORE commands permit system supervisors, system

managers, and other privileged users to copy ﬁles to tape. The RESTORE command can

purge and replace a database ﬁle with a different ﬁle from tape if the ﬁles have the same

name.

Account and Group Protection

To gain access to a TurboIMAGE/XL database, you must be able to access the ﬁles in the

account and group in which the database resides. The system manager and account

manager administer the security levels for accounts and groups. The system manager

creates accounts, and either the system or account manager creates new groups and users.

The system and account managers can prevent members of other accounts from accessing

the database by specifying access as user type AC (account member) for the account and

group containing the database. They can prevent users who are members of the account,

but not of the group, containing the database from accessing it by specifying GU (group

user) for the group access. On the other hand, they can allow access from other accounts by

specifying user type ANY at both the account and group levels.