A.FETCH B.FOUND C.ROWCOUNT D.ISOPEN
A.mount→open→nomount B.mount→open→close C.close→open→mount D.nomount→mount→open
A.Db_1\NETWORK\ADMIN\Listener.ora B.Db_1\NETWORK\ADMIN\tnsnames.ora C.Client_1\NETWORK\ADMIN\Listener.ora D.Client_1\NETWORK\ADMIN\tnsnames.ora