1) is there any easy way to determine whether a database link is "public" or private?
2) where would you be able to tell, are there any clues in the dba_db_links table?
3) what exactly is meant by "private" link, and how can you tell which users have access to use this "private" link? I am assuming "public" essentially means anyone with an account in the local database can access the remote database.
4) also when a database link is active, how does a user query tables in that database once logged into their local database. do you have to add a database.table.colum type prefix to your sql?