After installing oracle 11g on any machine it is running Very slow

Cause:-

If there is a entry for DNS server Oracle is trying to resolve a names into IP and is trying to reverse resolving a IP into names for every client connection. It is happen even for a connection from local server.

Resolution:-

1. Connect to database server using root.
2. Goto /etc directory.
3. Open resolv.cong file.
4. Remove any entry for DNS from that file.
5. Restart database.