creating indexes

If you want to improve the performance of some queries, you should consider creating an index. You can also use indexes to enforce uniqueness on a column or a collection of columns. At the end of this lesson, you should be able to
Distinguish between the indexes that are created automatically and those that are created manually.
Identify the uses for indexes.
Explain the index structure and why it improves query speed.
Create a non-unique index.
Remove an index from the data dictionary.
Evaluate guidelines for creating and using indexes....