The easiest way to delete a database instance is with the Installation Manager.
You can, however, also use the Database Manager CLI.
To delete a database instance, you first transfer it to the OFFLINE operational state. If you want to keep the database files, you can specify this with an option in the command for deleting the database instance.
Installation Manual, Using the Installation Manager
You want to delete the database instance DEMODB including all database files (system default value).
1. Call the Database Manager CLI in session mode, log on as operator DBM with the password DBM, connect to the database instance DEMODB:
>dbmcli –u DBM,DBM –d DEMODB
dbmcli on DEMODB>
2. Transfer the database instance to the OFFLINE operational state:
dbmcli on DEMODB>db_offline
3. Delete the database instance:
dbmcli on DEMODB>db_drop
You have deleted the database instance DEMODB.
You can confirm this by displaying the list of all existing database instances (see: Database Manager CLI, db_enum)