Dynamic Plan Migration for Continuous Queries Over Data Streams

Dynamic plan migration is concerned with the on-the-fly transition from one continuous query plan to a semantically equivalent yet more efficient plan. Migration is important for stream monitoring systems where long-running queries may have to withstand fluctuations in stream workloads and data characteristics. Existing migration methods generally adopt a pause-drain-resume strategy that pauses the processing of new data, purges all old data in the existing plan, until finally the new plan can be plugged into the system. However, these existing strategies do not address the problem of migrating query plans that contain stateful operators, such as joins. We now develop solutions for online plan migration for continuous stateful plans. In particular, in this paper, we propose two alternative strategies, called the moving state strategy and the parallel track strategy, one exploiting reusability and the second employs parallelism to seamlessly migrate between continuous join plans withou...

• Type: Conference
• Year: 2004
• Where: SIGMOD
• Authors: Yali Zhu, Elke A. Rundensteiner, George T. Heineman
• Keywords: Continuous Query Plan, Database, Dynamic Plan Migration, Online Plan Migration, SIGMOD 2004