HP-UX Directory Server 8.1 administrator guide

4. Highlight the DNA instance entry, and right-click on the Advanced link to open the property
editor.
5. Edit the DNA-related attributes.
3.7 Enforcing attribute uniqueness
Attribute uniqueness means that the Directory Server requires that all new or edited attributes
always have unique values. Attribute uniqueness is enforced through a plug-in. A new instance
of the Attribute Uniqueness Plug-in must be created for every attribute for which values must
be unique.
3.7.1 Overview of attribute uniqueness
The Attribute Uniqueness Plug-in is a preoperation plug-in. This means that the plug-in checks
all update operations before the server performs an LDAP operation. The plug-in determines
whether the operation applies to an attribute and a suffix that it is configured to monitor.
If an update operation applies to an attribute and suffix monitored by the plug-in and it would
cause two entries to have the same attribute value, then the server terminates the operation and
returns an LDAP_CONSTRAINT_VIOLATION error to the client.
Each instance of the Attribute Uniqueness Plug-in performs a check on a single attribute for one
or more subtrees. To check uniqueness of several attributes, a separate instance of the plug-in
must be created for each attribute to check.
138 Creating directory entries