刚刚接触Oracle,有些东西不明白。Basic登录明白，通过ip,端口什么的容易理解。Tns是什么？为什么我通过tns登录报异常
Status : Failure -Test failed: Listener refused the connection with the following error: ORA-12505, TNS:listener does not currently know of SID given in connect descriptor


GVPEFT01 =
(DESCRIPTION =
(ADDRESS_LIST =
(ADDRESS = (PROTOCOL = TCP)(HOST = segotl0865.srv.volvo.com)(PORT = 1523))
)
(CONNECT_DATA =
(SID = gvpeft01)
(SERVER = DEDICATED)
)
)

但是我通过basic方式连接，就能连上，这是为什么？