Category Archives: Oracle

some useful commands

//displays full database instance name:
select * from global_name;

//displays a sid(instance) name
select sys_context('userenv','instance_name') from dual;

//name of a logged user
select user from dual;

//name of a current instance
select instance from v$thread;

//name of a current instance
select name from v$database;


How to start Oracle database

1. Ensure that environment variables are set so that you connect to the desired Oracle instance:
set ORACLE_SID=instanceName
2. Start oracle instance without connecting to it
sqlplus /nolog
3. Connect to database as sysdba
connect username/password as sysdba