Function-Based Indexes

Database systems often provide methods for improving performance for computed columns. It is often good practice to derive data from several existing columns. However, these multi-column computations can be expensive to calculate at query time. Several techniques such as materialized views or function-based indexes can improve performance in these situations. In particular, function-based index structures store the calculated values for efficient retrieval. As part of an experiment, you can create a computed attribute and try queries with and without function-based indexes.