Creating a sequence object

Many applications require sequential numbers to be generated for key values such as the item number, invoices, and so on. Sequences offer a very good solution to such applications. Sequences are database objects that allow a user to generate key values automatically. Because these values are generated within the database, there is no chance of the duplicate values being present. DB2 keeps track of the values being generated and knows the next values, so even in the case of a crash or a failure, the new values are correct. It also gives better performance as compared to other approaches of generating the values manually. In this recipe, we will see how sequences can be created and used, and we will also see how it is different from an identity column. In this recipe, we will see how to create sequence objects.

Getting ready

The key aspect to consider before creating a sequence is the sequence behavior. DB2 automatically increments the sequence value based on the...