CS Degree Day 84

What I did today?

• Lecture 4: Query optimization - cost estimation, join ordering
• Lecture 5: Indexing - B+ trees, hash indexes
• Problem set: Explain query plans for sample queries

The B+ tree is everywhere. Every database index you have ever created is almost certainly a B+ tree. The structure maintains sorted order while keeping all leaves at the same depth. Insertions and deletions are O(log n). Range queries are efficient because the leaves are linked.