A method and apparatus for applying an application of a database service, such as X.500 or LDAP, to a relational database, a database design and use of the database to perform such services. Specifically addressed is the problem of database searching, particularly search speed and complexity of search. The method and apparatus concern searching a directory service database, in which the scope of search area is initially prescribed and/or in which a filter is applied over the search area. Moreover, in dealing with an alias during a search, a unique set of areas is found which define areas of a search tree that need to be searched. A FLAG column is used to indicate if an alias points inside a subtree. The method and apparatus also enable single pass resolution in any one of a search, filter or subtree search of a directory service, the method and apparatus including the use of a path column to simultaneously apply an arbitrary filter over an arbitrary subtree. Further disclosed is a method and apparatus of retrieving data from a directory service database, which includes conducting search, collecting all entries that need to be retrieved, and retrieving entries in parallel.