After you have started the application, you will see a prompt. In this console, you will write the commands with the help of assistant.
Suppose that you want to change a parameter of the database configuration. You start writing:
Now, you press the Tab key, and then, the assistant will complete the word. This is one of the functionalities of the application, the completion. At this time, the console has to be like this:
Without writing anything else, you press once again the Tab key. Here, the assistant will propose you a set of options for the command currently written. This is another functionality of the application, the proposition.
sa>db2 update admin database dbm sa>db2 update
Now, you can continue writing the command, just by writing one or two letters of the word, and the assistant will show you a list of options, or completing the word if there is only one option.
sa>db2 update database configuration using alt_collate app_ctl_heap_sz appgroup_mem_sz applheapsz archretrydelay . . . tsm_password userexit util_heap_sz vendoropt sa>db2 update database configuration using
When you are ready to execute a command, just press Enter.
Look at this article: http://en.wikipedia.org/wiki/Command_line_completion.