Like an index in a book, an index in a database lets you quickly find specific information in a table or indexed view. An index contains keys built from one or more columns in the table, or view, and pointers that map to the storage location of the specified data. You can significantly improve the performance of database queries and applications by creating well-designed indexes to support your queries. Indexes can reduce the amount of data that must be read to return the query result set. Indexes can also enforce uniqueness on the rows in a table, ensuring the data integrity of the table data.
The topics in this section provide the information to help you understand, design, implement, and optimize indexes.
Explains index concepts and includes descriptions of each index type available in SQL Server.
Provides guidelines, rules, and restrictions you should know when you design an index.
Provides guidelines, rules, and restrictions you should know when you create, modifying, or dropping an index.
Provides specific guidelines and tips for maintaining index performance and maximizing index operations.