Parallelization for complex query based on OGSA-DAI
The complex JOIN query is the most expensive relational operation defined by relational algebra. One way to speedup query execution is to adopt the parallel join processing. This paper investigates methods for parallel execution of join queries and analyzes their performance. Firstly we introduce the mechanism defined in OGSA-DAI middleware developed by Edinburgh University. Secondly we analyze possible parallel mechanisms for complex join query. Thirdly we propose two parallel join algorithms-Hash Split Join algorithm and Sorted Merge Join algorithm, which are designed by using OGSA-DAI class. Lastly based on our experiments, we analyze respectively the performance of every functional activity.