Indexing can affect the performance of a general-purpose database that has roughly equal numbers of fetches and changes. The decision to add an index can improve the performance of a system but can also degrade it. With these thoughts in mind, address the following:

When would creating an index reduce overall database performance? Explain.

Describe and explain a situation where an index would increase the performance of some database operations but degrade the performance of other operations.

How could you resolve a situation in which you are not sure whether an index will help or harm overall database performance?