Evolution and Revolutions in LDAP Directory Caches

LDAP directories have recently proliferated with the growth of the Internet, and are being used in a wide variety of network-based applications. In this paper, we propose the use of generalized queries, referred to as query templates, obtained by generalizing individual user queries, as the semantic basis for low overhead, high beneet LDAP directory caches for handling declarative queries. We present eecient in-cremental algorithms that, given a sequence of user queries, maintain a set of potentially beneecial candidate query templates, and select a subset of these candidates for admission into the directory cache. A novel feature of our algorithms is their ability to deal with overlapping query templates. Finally, we demonstrate the advantages of template caches over query caches, with an experimental study based on real data and a prototype implementation of the LDAP directory cache.