官方文档:
Typically, a database link has the same name as the global database name of the remote database that it references. For example, if the global database name of a database is sales.us.oracle.com, then the database link is also called sales.us.oracle.com.
When you set the initialization parameter GLOBAL_NAMES to TRUE, the database ensures that the name of the database link is the same as the global database name of the remote database. For example, if the global database name for hq is hq.acme.com, and GLOBAL_NAMES is TRUE, then the link name must be called hq.acme.com. Note that the database checks the domain part of the global database name as stored in the data dictionary, not the DB_DOMAIN setting in the initialization parameter file (see "Changing the Domain in a Global Database Name").
If you set the initialization parameter GLOBAL_NAMES to FALSE, then you are not required to use global naming. You can then name the database link whatever you want. For example, you can name a database link to hq.acme.com as foo.
Note:
Oracle recommends that you use global naming because many useful features, including Replication, require global naming.
After you have enabled global naming, database links are essentially transparent to users of a distributed database because the name of a database link is the same as the global name of the database to which the link points. For example, the following statement creates a database link in the local database to remote database sales:
CREATE PUBLIC DATABASE LINK sales.division3.acme.com USING 'sales1';
See Also:
Oracle Database Reference for more information about specifying the initialization parameter GLOBAL_NAMES
GLOBAL_NAMES的含义:
GLOBAL_NAMES
Property |
Description |
Parameter type |
Boolean |
Default value |
false |
Modifiable |
ALTER SESSION, ALTER SYSTEM |
Range of values |
true | false |
Basic |
No |
GLOBAL_NAMES specifies whether a database link is required to have the same name as the database to which it connects.
If the value of GLOBAL_NAMES is false, then no check is performed. If you use or plan to use distributed processing, then Oracle recommends that you set this parameter to true to ensure the use of consistent naming conventions for databases and links in a networked environment.