1. Alexandria Digital Library Projects Alexandria Digital Earth Prototype Greg Janée Middleware architecture HTTP transport JIGISDLIP proxy web browser Bucket99 driverquery translator MIDDLEWAREMIDDLEWARE CLIENTCLIENT SERVERSERVER web intermediary/ XML  HTML converter configuration file core functionality access control (service- and collection-level) query fan-out & results merging query result ranking result set caching access control mechanisms ranking methods client-side services (Java classes) server-side interface (Java interfaces) RDBMS JDBC configuration files, scripts RMI transport proxy driver HTTP XML group driver

2. Alexandria Digital Library Projects Alexandria Digital Earth Prototype Greg Janée Collection population collection driver per content standard adheres to searchable metadata bucket view scan view other views (optional) indexes derives produces executes metadata view(s) CREATE IMPORT collection-level metadata ------- mappings statistics thesauri buckets updates middleware collection driver native XML metadata XML schema XSLT transform(s)

3. Alexandria Digital Library Projects Alexandria Digital Earth Prototype Greg Janée Generic RDBMS driver query driver translator Python translator vocabulary RDBMS coded vocabulary metadata driver subdriver template-based report template w/ embedded references URL-based, etc. universal join script config RDBMS schema description paradigm library connection pool query thread RDBMS queries collection driver offline s/w collection- level metadata RDBMS static metadata config RDBMS

4. Alexandria Digital Library Projects Alexandria Digital Earth Prototype Greg Janée Gazetteer service protocol o Formal model  identifiers, names, footprints, types, relationships, current vs. historical, primary vs. secondary o Query language  by name, by footprint, by type, by relationship  boolean combinations of the above o Metadata  brief, full o Services  query, harvest, metadata  create, update, delete o XML encodings