Check if db-link works or not

Question

hi,
does anybody know how to check if a database-link works or not, using an pl/sql-procedure or function?
thanks in advance,
regards

Answer 1

If the dblink is down then it should generate an exception. It won't be "tnsname could not be resolved" because the tns name is picked up from the client or source server tnsnames file, so it'll be able to resolve the name, but will have some other exception. It's more likely to be...
SQL> select * from dual@fred;
select * from dual@fred
ERROR at line 1:
ORA-12545: Connect failed because target host or object does not exist
SQL>Edit: NOTE: I created a tnsnames entry for fred prior to this, otherwise I would have got...
SQL> select * from dual@bob;
select * from dual@bob
ERROR at line 1:
ORA-02019: connection description for remote database not found
SQL>If there's no database link created for that name
or
SQL> select * from dual@bob;
select * from dual@bob
ERROR at line 1:
ORA-12154: TNS:could not resolve the connect identifier specified
SQL>If there's a database link for bob but no tnsname entry.
Message was edited by:
blushadow