Oracle - DB Links

There are times where tables are not able to be accessed with a regular select statement. These tables might be available via db link.

For example let’s say I have a table named:

• my_tbl

If I try to query this table I get an error.

SQL> select * from my_tbl where ROOWNUM < 2;
 
Error starting at line : 1 in command -
select * from my_tbl where ROOWNUM < 2
Error at Command Line : 1 Column 15
Error report - 
SQL Error: ORA-00942L table or view does not exist
00942. 00000 - "table or view does not exist"
*Cause:
*Action:

Let’s find the correct DB link:

select * from all_db_links;

Now what I do is try the select statement with every db link name from the query above and see which one works.

For example:

select @ from my_tbl@paste_db_link_here where rownum < 2;