Parallelism with IBM's relational Database2 (DB2)

The current use of parallelism in the IBM Database2 (DB2) is discussed, along with future trends. Parallelism is necessary for relational database managers to achieve modern performance goals of high throughput for both homogeneous and heterogeneous workloads and fast response times for increasingly complex queries. A transaction appears to DB2 as a set of serially requested database operations using the Structured Query Languages (SQL). High throughput levels are achieved by multiprocessing. Multiprocessing levels in excess of a hundred are quite common. DB2 provides peer-to-peer communication, allowing applications on one DB2 computer system to access data on another DB2 computer system. That implementation is more favorable for ad hoc queries than for transactions. Parallelism plays a key role in DB2's performance, where it is most visible in intertransaction multiprocessing to achieve high throughput and, to a lesser extent, in intraquery parallelism to reduce response time.< >