问题
I went in TOAD and put in the TNS name for a db that was supplied to me by the DBA. I also put in the user and password and it connected fine. My confusion is that the tnsnames.ora file does not have any entry corresponding to that db name. So how is TOAD resolving the DB name?
回答1:
In your Oracle client, the ldap.ora file can list one or more ldap server names, which can be queried to get the Oracle instance info for the given TNS name. This way, TOAD (and other apps) can resolve Oracle database names that are not listed in the tnsnames.ora file.
来源：https://stackoverflow.com/questions/11890387/toad-connects-despite-the-db-name-not-being-present-in-tnsnames-ora