The right index on the right column, or columns, is the basis on which query tuning begins. A missing index or an index placed on the wrong column, or columns, can be the basis for all performance problems starting with basic data access, continuing through joins, and ending in filtering clauses. For these reasons, it is extremely important for everyone—not just a DBA—to understand the different indexing techniques that can be used to optimize the database design.
In this chapter, I cover the following topics:
What an index is
The benefits and overhead ...
