Netscape DIRECTORY SERVER 6.2 - ADMINISTRATOR Administrator's Manual page 498

Overview of the Attribute Uniqueness Plug-In
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
client.
The attribute uniqueness plug-in performs a check on:
• A single attribute
• One or several subtrees
If you want to check uniqueness of several attributes, you must create a separate
instance of the plug-in for each attribute you want to check.
You can also configure how the attribute uniqueness plug-in operates:
• It can check every entry in the subtrees you specify.
For example, if your company,
example_a.com and example_b.com, when you add an entry such as
uid=jdoe,ou=people,o=example_a,dc=example,dc=com
enforce uniqueness only in the
You can do this by listing the DN of the subtree explicitly in the uid
uniqueness plug-in configuration.
This configuration option is explained in more detail in "Specifying a Suffix or
Subtree," on page 505.
• You can specify an object class pertaining to an entry in the DN of the updated
entry, and perform the uniqueness check on all the entries beneath it.
This option is useful in hosted environments. For example, when you add an
entry such as
you can enforce uniqueness under the
subtree without listing this subtree explicitly in the configuration, but
instead, by indicating a marker object class. If you specify that the marker
object class is
entry in the DN that has this object class (
check on all entries beneath it.
Additionally, you can specify to check uniqueness only if the updated entry
includes a specified object class. For example, you could specify to perform the
check only if the updated entry includes
This configuration option is explained in more detail in "Using the
markerObjectClass and requiredObjectClass Keywords," on page 506.
If you intend to use the attribute uniqueness plug-in in a replicated environment,
refer to "Replication and the Attribute Uniqueness Plug-In," on page 509.
498 Netscape Directory Server Administrator's Guide • December 2003
example.com
o=example_a,dc=example,dc=com
uid=jdoe,ou=people,o=example_a,dc=example,dc=com
, the uniqueness check algorithm locates the
organization
LDAP_CONSTRAINT_VIOLATION
, hosts the directories for
o=example_a,dc=example,dc=com
) and performs the
o=example_a
objectclass=inetorgperson
error to the
, you need to
subtree.
,
.