Asynchronous View Maintenance for VLSD Databases
The query models of the recent generation of Very Large Scale Distributed (VLSD) shared-nothing data storage systems, including the own PNUTS and others (e.g. BigTable, Dynamo, Cassandra, etc.) are intentionally simple, focusing on simple lookups and scans and trading query expressiveness for massive scale. Indexes and views can expand the query expressiveness of such systems by materializing more complex access paths and query results. In this paper, the authors examine mechanisms to implement indexes and views in a massive scale distributed database. For web applications, minimizing update latencies is critical, so they advocate deferring the work of maintaining views and indexes as much as possible.