Over the years I have thought long and hard about an intelligent way of naming databases, this is only for Oracle environments.
Naming of the database instances should identify immediately what database and instance number it is. I have seen many times where the instance number is not identified and makes it difficult when managing a large environment to keep it all straight.
Instance naming is as follows:
AAAAAXYYZ
AAAAA = This is a 5 char value for the application naming or suite. This can be something that everyone can recognize for a particular app or collection of apps. I always try to make it 5 characters even if I have to "fill" space. This keeps all names the same length, especially when sorting the names of the databases and instances, plus allows an exact match without the worry of spaces.
X = Database usage type (see post of usage types for environments) this can includes things such as "Test", "Production", etc.
YY = Sequential identifier for multiple databases of the same usage types within a particular cluster. So if you had two or three "Test" databases you'd have T01, T02, T03, etc.
Z = Node sequence as used in RAC databases. This would identify the node number in a cluster.
Ex: MRCXXT011 / MRCXXT012
This would identify an instance as being an instance associated with the MRCXXT01 database, and added a suffix in order to identify this as the “1” instance of this database. Instance name can be up to 16 characters and therefore could have additional characters in the event more than 9 nodes were necessary.
In the case of RAC One Node, an “_1” for current running instance, and “_2” for failover instance, is automatically appended to the instance name and is not an option to change this, as Oracle automatically enforces this. For example:
Ex: MRCXXT01_1 / MRCXXT01_2
This would immediately identify an instances as being a RAC One Node (RON) instances associated with the MRCXXT01 database, and an automatically added a suffix in order to identify this as the “_1” or “_2” instance of this database. Instance name can be up to 16 characters and therefore could have additional characters in the event more than 9 nodes were necessary.