It depends on what name you want to change in the database. Usually, database name can be DB_NAME, DB_UNIQUE_NAME or both in Oracle.
We have introduced the procedures to rename DB_NAME, DB_UNIQUE_NAME or both as following.
- Changing Database Name (DB_NAME)
- Changing Database Unique Name (DB_UNIQUE_NAME)
- Changing Both Database Name and Database Unique Name
Various names in Oracle might confuse you for a while, you may check the differences among DB_NAME, DB_UNIQUE_NAME, SERVICE_NAME, INSTANCE_NAME and ORACLE_SID.