High Performance Active Database Management on a Shared-Nothing Parallel Processor

摘要

A new type of system for testing trigger conditions and running trigger actions outside of a DBMS was designed as part of this project. Such a system is called an asynchronous trigger processor since it processes triggers asynchronously, after triggering updates have committed in the source database. The architecture of a prototype asynchronous trigger processor called TriggerMan is described. TriggerMan is designed to be able to gather updates from a wide variety of sources, including relational databases, object-relational databases, legacy databases, flat files, the web, and others. TriggerMan achieves the ability to gather updates from so many sources using an extensible data source mechanism. TriggerMan can make use of the asynchronous replication features of commercial database products to gather updates. When cooperating with a source DBMS with direct support for asynchronous replication, TriggerMan can gather updates in an efficient and robust manner. TriggerMan supports simple, single- table (single data-source) triggers, as well as sophisticated multiple-table (multiple-data-source) triggers. It also will support temporal triggers using an extensible temporal function mechanism. Moreover, TriggerMan takes advantage of parallelism for high performance, utilizing a shared-nothing model of parallel computation.