关于 Global Database Name

Global name

A global name refers to the full name of a database (including its domain) which uniquely identifies it from any other database. An example global name might be FaqDB1.orafaq.com.

If you set the GLOBAL_NAMES parameter to TRUE, all database link names must be valid global names.

If you do not specify a SERVICE_NAME for a database, the service name will default to the database's global name.

To query a database's global name:

SELECT * FROM global_name;
      

Use the following procedure to change the domain in a global database name:

1. Determine the current global database name. For example, issue:

SELECT * FROM GLOBAL_NAME;

GLOBAL_NAME

----------------------------------------------------------------------------

SALES.AU.ORACLE.COM

2. Rename the global database name using an ALTER DATABASE statement. For

example, enter:

ALTER DATABASE RENAME GLOBAL_NAME TO sales.us.oracle.com;

3. Query the GLOBAL_NAME table to check the new name. For example, enter:

SELECT * FROM GLOBAL_NAME;

GLOBAL_NAME

----------------------------------------------------------------------------

SALES.US.ORACLE.COM

SID = identifies the database instance (database name + instance number). So if your database name is somedb and your instance number is 3, then your SID is somedb3.

DB Name = Name of the database (database can be shared b/t multiple instances)

DB Domain = Usually the same as your company domain (somecompany.com)

Global Database Name = Database name + database domain (somedb.somecompany.com)

Service Name = A "connector" to one or more instances. It is often useful to create additional service names in a RAC environment since the service can be modified to use particular SIDs as primary or secondary connections, or to not use certain SIDs at all.

Service Alias = An alias to the service name (just like a CNAME, etc). Say you make your service name something meaningful to the dba, but perhaps it's a bit esoteric. Create a service alias and name it something that will be meaningful to the user.

Instance name = same as SID