Database Name (DB_NAME), database instance name (instance_name), operating system environment variable Oracle_sid, database service name (service_name), database domain name (db_domain), global database name (global_db_name) is a concept that is easily confused using Oracle database.
1, database name and instance name
× Database Name (DB_NAME): It is the internal ID of the data (ie, is used inside the Oracle database) because it is saved more in the database, and the control file is saved in binary, so it is difficult to change its name (it is difficult No, it's ok, it's okay to change it.
There is a db_name parameter in the PFile is it.
Database name: Internal tag, use the database name in the database installation, creation, creation control file, modify the database structure, use the database backup and recovery (not to use what SID ...)
This value is used when ALTER DATABASE is used.
View: You can see the parameters (multiple methods, show parameter db_name, etc.) or check V $ Database view
Modify the database name: 略, there is a jar
× instance name
Instance name (instance_name): Connection between the operating system (using the external connection), a database can have multiple instances (parallel service). To connect with a database server, you must know that it is unique, and the light knows that the database name is useless.
There is instance_name parameter in the PFile, in fact, the general settings are the same as the database name (different is self-found, can be more likely to change this parameter.
View: See parameters
INSTANCE_NAME Difference to Oralce_SID:
It is all index names, but oracle_sid is the environment variable setting of the operating system, interacting with the operating system, and the value must be the same as instance_name, and instance_name can be found in the parameter file (explain white)
(Need to note 2000 Note that the modification related parameters in the registry are Oracle_SID)
In the network service configuration (the old protocol is not said), there is an option in Net8i that is the SID configuration means the ORALCE_SID name! (4i's new service configuration is described later)
2, database domain name and service name (name introduced after 8i)
× Database Domain Name: Similar network domain names, (so a database name DB_NAME can be the same in different fields)
Determine when installation (filled in the global database name), the definition rule is similar to the network definition.
DB_DOMAIN in the parameter file, there is no such global database name, the database name, the database does not use domain name
Inquire:
× Global Database Name: = DB_NAME DB_DOMAIN, if there is no db_domain, then ...
× Database Service Name (Service_Names); this is not your concept of network services you configured in the client (you want to distinguish !!!), this is the concept of the database itself! ! !
Defined as = global database name (refer to the definition of the global database name, there is branch, if there is domain name, the service name = ..., no domain name ...) Parameter file service_names
In the new NET Services network service provided in 9i, it is recommended to use this type of connection (Net8i can also be equipped)
Domain names can be easily modified (change parameters can be restarted)
