This lecture will cover various issues related to the physical storage of relations on disk, as well as index data structures we might use to efficient access those stored relations.

• Read Chapter 2 on B+Tree basics in Database Internals by Alex Petrov.
• Beckmann et al. The R*-Tree: An Efficient and Robust Access Method for Points and Rectangles. In Red Book. [PDF]

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

• Under what circumstances is a secondary index superior to a sequential (in-order) scan of a heap file? Under what circumstances would the secondary index scan be preferable?
• What is the purpose of the neighbor pointers in a B+Tree? When are they useful?
• Why are B+Trees insufficient for storing and indexing the types of data stored by R*-Trees?