Connect as sys - When you use just " / "

When connecting as sys, you can use just " / " when:

- Your user account in Windows  belong to ora-dba group, and
-  On your sqlnet.ora, it should be setup:

 SQLNET.AUTHENTICATION_SERVICES = (NTS)

Now you can do:

C:\ SET ORACLE_SID=<My_Instance> 
C:\ sqlplus /nolog

SQL> connect / as sysdba

Archived Redo Logs - Who is making too many

Query to determine what user, suddenly, is making too many archived redo logs:

  SELECT s.sid, s.serial#, s.username, s.program, i.block_changes 
  FROM v$session s, v$sess_io i
      WHERE s.sid = i.sid   
      ORDER BY 5 desc, 1, 2, 3, 4

The one(s) that is(are) on top, are the guilty user(s).

How to drop a Primary Key

Alter table <Schema>.<Table> drop constraint <Name_of_Primary_ Key>  ;

How to switch to a different Schema

ALTER SESSION SET CURRENT_SCHEMA = <My_Schema>;