Reactive Database Research Group, ASU

August 2007 - May 2011

Distributed Event Processing Agents (DEPAs)   Small arrow  Visit the Website
The main focus of this research project is to define and incrementally maintain materialized views over heterogeneous structured data sources in an event stream processing environment for optimizing the execution of enterprise applications. Streams are used as a communication paradigm in this framework. Each agent, known as a Distributed Event-stream Processing Agent (DEPA), maintains or subscribes to resources, such as data and event streams as well as relational and structured XML data sources. These DEPAs are capable of handling data streams from different data sources, such as application event generators, the output from continuous queries over sensor data, and streams of incremental changes from databases. Each stream has an associated schema, and is assumed to be either in a relational or XML format. Each DEPA has a specific responsibility within the distributed application, which increases the probability of identifying common subexpressions on which to define materialized views for improving performance.
  • Developed a service-based metadata repository that provides schema-level information regarding the different sources, such as relational, XML data sources, events and data streams, hybrid queries over relational and XML data sources
  • Designed a mixed multigraph model to represent the heterogeneous query expressions under a common graph model and a heuristics-based algorithm to detect common subexpressions from the common graph model over relational and structured XML data sources
  • Defined LINQ-based hybrid materialized views that retain the data in their native format
  • Incrementally maintain these hybrid views using magic sets optimization technique