DBLINKにTnsnamesを直接設定する
Usingに直接接続場所を設定する。
CREATE DATABASE LINK MY_LINK CONNECT TO MYDB IDENTIFIED BY MYDB USING '(DESCRIPTION= (ADDRESS= (PROTOCOL=TCP) (HOST=ipaddress) (PORT=1521)) (CONNECT_DATA= (SID=orcl)))'
CREATE DATABASE LINK MY_LINK CONNECT TO MYDB IDENTIFIED BY MYDB USING '(DESCRIPTION= (ADDRESS= (PROTOCOL=TCP) (HOST=ipaddress) (PORT=1521)) (CONNECT_DATA= (SID=orcl)))'