Modifying Indexes, CALC Keys, and Referential Constraints › Maintaining Indexes › Creating an Index

Creating an Index

To create a new index on a column or columns in a table, use the SQL DDL CREATE INDEX statement. If the index is going to map to a new area, see Defining Segments, Files, and Areas for information about defining an area.

Considerations

• If you specify that the index is unique, and data in the key columns is not unique, you will receive an error and the index will not be created.
• Each index implies additional runtime processing to handle INSERT, UPDATE, and DELETE statements for the index itself.

Note: For more information about designing indexes, see the Database Design Guide.

Example

In the following example, an index is built on the LAST_NAME column in the BENEFITS table.

create index be_lname (last_name) on emp.benefits;