Xiaoyi Xu (MSC Graduate:  Sept 1999 - Nov 2001)


Thesis: "A Clustering Approach to Configuring Buffer Pools in a Database Management System"


Abstract (full text not available)

Database Management Systems (DBMSs) use a main memory area as a buffer to reduce the number of disk accesses performed by a transaction.  This memory is a key resource in a DBMS.  Current DBMSs such as DB2 Universal Database, divide the buffer area into a number of independent buffer pools.  Each database object (table or index) is assigned to a specific buffer pool.  The tasks of configuring the buffer pools, which defines the mapping of database objects to buffer pools and setting a size for each of the buffer pools, is crucial for achieving optimal performance.

Mapping database objects to buffer pools, which we refer to as "the buffer pool configuration problem", is the focus of this thesis research.  Mapping database objects to buffer pools can be viewed as a partitioning problem, that is, we partition the database objects into groups where each group goes to one buffer pool.  The partitioning of objects is based on how the objects are used and on the inherent properties of objects.  

This thesis presents an approach to the configuration problem based on analyzing access patterns to database objects in a given database workload.  The approach is discussed, implemented and verified against the TPC-C benchmark database. The performance metrics used to evaluate the algorithms are the weighted response time, throughput, and percentage of physical reads for the given workload.