This step is optional. To enhance performance, Sybase recommends creating a unique index that contains only the IDENTITY column. For example, to create a unique index named reviews_id on the IDENTITY column created in step 2, issue the command:
create unique index reviews_id on reviews(id)
For more information about creating a unique index, see Chapter 11, “Creating Indexes on Tables,” of the Transact-SQL User’s Guide.
