Creation of indexes

Indexes provide efficient access to table data, but can require additional processing when you modify data in a table.

You can create indexes to enforce uniqueness. You can also choose to use indexes because of access requirements.

Using indexes involves a trade-off. A greater number of indexes can simultaneously improve the performance of a certain transaction and require additional processing for inserting, updating, and deleting index keys.

After you create an index, DB2® maintains the index, but you can perform necessary maintenance, such as reorganizing it or recovering it, as necessary.