oracle change dblink password
ALTER DATABASE LINK private_link
CONNECT TO hr IDENTIFIED BY hr_new_password;
ALTER PUBLIC DATABASE LINK public_link
CONNECT TO scott IDENTIFIED BY scott_new_password;
ALTER SHARED PUBLIC DATABASE LINK shared_pub_link
CONNECT TO scott IDENTIFIED BY scott_new_password
AUTHENTICATED BY hr IDENTIFIED BY hr_new_password;
ALTER SHARED DATABASE LINK shared_pub_link
CONNECT TO scott IDENTIFIED BY scott_new_password;