Question

I am currently trying to validate that an Oracle db_link is actually pointing to the correct server.
When I query the db_links I get the definition of the DB_link referencing the TNSNames:

select * from all_db_links;

Gives me the following result:

OWNER: user1
DB_LINK: DBL_xxx.world
Username: User2
Host: tnsEntry1
Created: 03-MAY-12

When I test the DB_link, everything works fine:

select * from dual@"DBL_xxx.world";

DUMMY: X

However, as I do not have access to the server, I cannot make sure that the tns entry tnsEntry1 is pointed to the correct server.

Locally, I can run:

select sys_context ( 'USERENV', 'DB_NAME' ) db_name,
 sys_context ( 'USERENV', 'SESSION_USER' ) user_name,
 sys_context ( 'USERENV', 'SERVER_HOST' ) db_host
 from dual;

I tried to run the same command remotely:

select sys_context ( 'USERENV', 'DB_NAME' ) db_name,
 sys_context ( 'USERENV', 'SESSION_USER' ) user_name,
 sys_context ( 'USERENV', 'SERVER_HOST' ) db_host
 from dual@DBL_xxx.world;

But it returns only local data.

Is there a way to check the remote info? Or check the tnsnames from a sql query?

Answer 1

This will give you the database name of the database on the other end of the database link:

select property_value 
from database_properties@<database_link> 
where property_name='GLOBAL_DB_NAME'