Connecting to SQL PLUS:
oracle> source /fmwapps/oracle/product/12.1.0/dbhome_1/bin/oraenv
Oracle_sid = ? [Enter SID of the instance you are trying to connect] orcl
oracle> sqlplus
To Start the instance
SQL*Plus: Release 12.1.0.1.0 Production on Sun Jun 29 12:06:50 2014
Copyright (c) 1982, 2013, Oracle. All rights reserved.
Enter user-name: SYS as SYSDBA
Enter Password: <Enter your DB password>
SQL> startup
To Shutdown the instance:
SQL> shutdown
To Find hostname of the Instance
SQL> select host_name from v$instance;
To find the port of the instance :
$ORACLE_HOME/11.2.0.3/network/admin
listerner.ora file has port and SID.
tnsnames.ora file has the cluster configuration for the database.
To fine the status of the listener:
lsnrctl status LISTENER
