Text Search in an NFS-Proxy: A Case Study in Extensible File Systems

This paper describes the design of an extensible 3-tiered semantic file system, backed by an existing extensible object-relational database. The system is designed to export the standard NFS interface, while providing indexing and query support for user-defined file types using the virtual directory abstraction. To illustrate the feasibility of the proposed architecture, we describe its implementation for one important file type, text. Indexing and query support for text are implemented in the database using a plug-in module, and support for full-text queries, including boolean keyword search and information retrieval rank, are exported by the file system interface using virtual directories.