A substring index is used to match values specified with wildcards in the filter. Substring indexes can be expensive to maintain, especially for large attribute values.
$ ldapsearch --port 1389 --baseDN dc=example,dc=com "(cn=Barb*)" cn dn: uid=bfrancis,ou=People,dc=example,dc=com cn: Barbara Francis dn: uid=bhal2,ou=People,dc=example,dc=com cn: Barbara Hall dn: uid=bjablons,ou=People,dc=example,dc=com cn: Barbara Jablonski dn: uid=bjensen,ou=People,dc=example,dc=com cn: Barbara Jensen cn: Babs Jensen dn: uid=bmaddox,ou=People,dc=example,dc=com cn: Barbara Maddox
