i am tring to use db link for that i have first change the name of both databases to sol1(remote) and sol3(local) then i create a db-link on sol3 CREATE DATABASE LINK SOL1.SWORLD CONNECT TO TEST IDENTIFIED BY TEST USING SOL1; LINK CREATED ON SQL / SELECT * FROM [email protected] MASSAGE SQL COULD NOT RESOLVE THE SERVICE NAME THEN I DROP THE DATABASE LINK AND CREATE A LINK FROM ORACLE ENTERPRISE SCHEMA MANAGER I CREATE A PUBLIC LINK OF FIXED USER AFTED LOGIN AND PASSWORD I ADD THE NAME IN SERVICE TAB AS SOL1 WHEN I TEST TAHT CONNECTION MASSAGE APPERAR LINK IS NOT ACTIVE