Easy to confuse terms: original: http://www.cnoug.org/viewthread.php? TID = 16803
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DB_NAME: The unique identifier of a database (Oracle Database), which is the Oracle Database, which is said in the first chapter. This representation is sufficient for a single database, but with the popularity of a distributed database composed of a plurality of databases, this command database has a certain burden on the management of the database, because the names of each database may be the same, resulting in management The confusion. In order to solve this, the DB_DOMAIN parameters are introduced so that the identity of the database is determined by two parameters of db_name and db_domain, avoiding the confusion of management because of the database reign. This is similar to the management of machine names on the interconnection. We connect DB_NAME and DB_DOMAIN to two parameters to connect, represent a database, and call the name of the database to global_name, which extends DB_NAME. The DB_NAME parameter can only be composed of letters, numbers, '_', '#', '$', and up to 8 characters.
DB_DOMAIN: Defines the domain where a database is located. The domain is named with the 'domain' of the Internet, but the database administrator is determined according to the actual situation in order to better manage distributed databases. Of course, it is convenient to manage, it can be equal to the field of the Internet.
Global_name: Unique identifier for a database (Oracle Database), Oracle recommends this method to command the database. This value is that the database is determined, the default value is db_name. Db_domain. In the future, any modification of DB_NAME and DB_DOMAIN parameters will not affect the value of global_name. If you want to modify global_name, you can only modify with the alter Database Rename Global_name to
Service_name: This parameter is the new introduction of Oracle8i. Before 8i, we used SID to indicate an instance of the logo database, but in the Oracle's parallel environment, a database corresponds to multiple instances, which requires multiple network service names, setting cumbersome. In order to facilitate the settings in the parallel environment, the service_name parameter is introduced, which corresponds to a database, not an instance, and this parameter has many other benefits. The default value of this parameter is DB_NAME. Db_domain, that is, equal to GLOBAL_NAME. A database can correspond to multiple service_name to achieve a more flexible configuration. This parameter is not directly related to the SID, ie the service name must be the same as the SID.
NET Service Name: Network service name, can also be called Database Alias. It is required to access the database when the client program has access the database, and the client is shielded to the details of the server side, and the location of the database is transparent.
