Lectures: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23

Overview

This lecture will cover buffer and memory management strategies in database systems, as well as continue our discussion of indexing from last Thursday.

Read the following papers:

• Gray, Jim, and Goetz Graefe. "The Five-Minute Rule Ten Years Later, and Other Computer Storage Rules of Thumb." SIGMOD Record 26, no. 4 (1997): 63-68. Also in Readings in Database Systems. San Fransisco, CA: Morgan Kaufmann, 1998. ISBN: 1558605231 (aka the Red Book).
• Chou, Hong-Tai, and David DeWitt. "An Evaluation of Buffer Management Strategies for Relational Database Systems." In Proceedings of the VLDB Conference, 1985.

As you read, think about and come to class prepared to answer the following questions:

• How much better is the hot-set model than simple LRU? Under what circumstances is LRU a bad idea? Why can these techniques be applied in database systems but not operating systems?
• What is the five minute rule? Do you buy it?
• Why is there an optimal index page size? What happens if you pick a page size that is too big? Too small?