Question about database and service name

[Ramon E. Estevez]

Hi list,   Reading the OU manuals Oracle 9i DBA Fundamentals II , in chapter 2 page 12, found   1-) An oracle database is represented to clients as a service.    2-) A database can have one or more services associated with it.    3-) A database can be presented as multiple services and a service can be implemented as multiple database           instances.   For the No. 2 :       I interpret that I can have 2 or 3 or 4 services for just ONE DB.  Is that correct ?.  How can I do that ?   For the No. 3:       I interpret that I can refer to the same DB with differents names.   As far as I understand, the DB instance name is unique, it can't be changed.  So how can I create several services names for one DB.   Or is just a trick in the TNSNAMES.ORA and LISTENER.ORA files.   Please can anyone give some light in that, I am totally confused !!!     Ramon E. Estevez [EMAIL PROTECTED] 809-565-3121