This property caches user DNs (distinguished names) locally when derby.authentication.provider is set to LDAP and derby.authentication.ldap.searchFilter is
set to derby.user. When you provide a user DN with
this property, is able to avoid an LDAP search for that user's
DN before authenticating. For those users without DNs defined with this property, performs
a search using the default value of derby.authentication.ldap.searchFilter.