Zusheng Xu (MSC Graduate: Sept 1999 - April 2001)


Thesis: "Automatically Scheduling Database Utilities"


Abstract (full text not available)

Current database management systems (DBMSs) require careful database configuration and maintenance for good performance.  Database system administration is a complex task, often requiring expert knowledge of database design and application behaviour.  Expert database administrators are required to configure and maintain an enterprise-class database, which increases the cost of DBMS ownership.  Automating the administration tasks is crucial to making DBMSs more affordable.

Data maintenance is one of the important administrative tasks in DBMSs.  Database administrators use data maintenance utilities to ensure the data in tables are stored as efficiently as possible.  Without data maintenance, the performance of applications will decrease but executing maintenance utilities interferes with running applications.  Scheduling and executing the utilities properly is therefore crucial to preventing applications from suffering major performance degradation.

The aim of this thesis is to find a usable algorithm to automatically schedule database utilities so that the performance degradation of applications is minimal.  The scheduling problem is formulated as a combinatorial optimization problem.  Four local (or heuristic) search algorithms, greedy search, simulated annealing, tabu search, and genetic algorithm are implement and evaluated for solving the database utilities scheduling problem.  Experimental results show that the tabu search algorithm is the best algorithm in terms of the quality of the schedule, the level of consistency, and scheduling speed.  The effectiveness of the tabu search algorithm is future demonstrated by also solving two large "real-world" database utilities scheduling problems.