Lightweight directory access protocol (LDAP) directory server cache mechanism and method

1. Technical Field A method of hierarchical LDAP searching in an LDAP directory service having a relational database management system (DBMS) as a backing store. The method begins in response to a search query to the relational database. Search results retrieved in response to the search query are cached, preferably in a pair of caches in the directory service. The first cache receives a set of identifiers indexed by a filter key of the search query. The search results, namely entries corresponding to the set of identifiers, are then stored in the second cache. In response to subsequent issuance of the search query, the cached search results are then used in lieu of accessing the relational database to increase search efficiency. To maintain the integrity of the cached information, routines are provided to invalidate the caches during given directory service operations.