HP-UX Directory Server Administrator Guide HP-UX Directory Server Version 8.1 (5900-3098, May 2013)

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.
The Attribute Uniqueness Plug-in can operate in specific, user-defined ways:
• It can check every entry in the specified subtrees.
For example, if a company, example.com, hosts the directories for example_a.com and
example_b.com, when an entry such as
138 Creating Directory Entries