Instance in database can be described as background process and memory structure or environment that contains access to databases.
Instance can be usefull to separate development, test, and production environment on one database server. Also you can manage multi-tenant/customers into several instances. So, it easier to manage multi customer application/database rather than combining into one database.
DB2, off course, support instance.
To list all instance created, open IBM DB2 command window and type “db2ilist”.
Create db2 instance: Open IBM DB2 command window, type “db2icrt mydev”.
Drop db2 instance type “db2idrop mydev”.
After you created the instance then set current instance with “set db2intance=mydev”.
Start instance service type “db2start”. To stop instance type “db2stop”.
You can see the current instance with “db2 get instance”.
On windows OS, you can see the instance process (service) on microsoft management console. Open run and type “services.msc”.