Planning and Managing Indexes

Indexes on commonly used tables might improve query and transaction processing. However, you should plan indexes carefully for your data and applications to avoid wasting the disk space required by indexes and the processing time required by index updates.

For general information about analyzing how queries and transactions use indexes, see Evaluate Index Use. For information about creating indexes for specific kinds of applications, see Create Appropriate Indexes for Queries and Create Appropriate Indexes for Transactions.

You can create more than one index on a single table. In some cases, the query optimizer can choose to use more than one index in query processing. Primarily, however, multiple indexes on a table allow the optimizer to choose the index that provides the most efficient query plan.