Database Software

DB version: 10.2.0.1.0


Question1.
I always used netmanager to add a TNS entry. But, for RAC, i see extra options like

FAILOVER_MODE =
        (TYPE = SELECT)
        (METHOD = BASIC)
        (RETRIES = 30)
        (DELAY = 5)

I don't find these options in netmanager. So Copy-paste is the only option left. Right?


Question2:
We have a RAC db with 2 nodes. My colleague sent me his tnsnames.ora file. In it, i can see one entry for the database (myracdb)
and two extra TNS entries (myracdb1 and myracdb2) for the two instances.

myracdb =
  (DESCRIPTION =
    (LOAD_BALANCE = YES)
    (ADDRESS = (PROTOCOL = TCP)(HOST = 10.80.10.178)(PORT = 1521))
    (ADDRESS = (PROTOCOL = TCP)(HOST = 10.80.10.180)(PORT = 1521))
    (ADDRESS = (PROTOCOL = TCP)(HOST = 10.80.10.190)(PORT = 1521))
    (ADDRESS = (PROTOCOL = TCP)(HOST = 10.80.10.200)(PORT = 1521))
    (CONNECT_DATA =
      (Service_name = myracdb)
      (FAILOVER_MODE =
        (TYPE = SELECT)
        (METHOD = BASIC)
        (RETRIES = 20)
        (DELAY = 5)
      )
    )
  )
  
  

myracdb1 =
  (DESCRIPTION =
    (ADDRESS_LIST =
      (ADDRESS = (PROTOCOL = TCP)(HOST = 10.80.10.178)(PORT = 1521))
    )
    (CONNECT_DATA =
      (sid= myracdb1)
    )
  )

myracdb2 =
  (DESCRIPTION =
    (ADDRESS_LIST =
      (ADDRESS = (PROTOCOL = TCP)(HOST = 10.80.10.180)(PORT = 1521))
    )
    (CONNECT_DATA =
      (sid= myracdb2)
    )
  ) 

Why do we need 2 tns entries for 2 rac nodes? Isn't one entry(myracdb) for the database enough?