I have an Oracle 10g database which is connected to another server with instance client. Problem is all of users(SYS/SYSTEM/SYSMAN/FATASAN/JAVAHER) are expired (I forgot to change expire date) and also sqlpus and instance client are faced with ORA-12560 error (Both servers were good but now I have no connection to data!)
How can I login into my own database when all usernames are expired ?!
Login to database server as the Oracle software owner (or, in case of Windows, as user who is member of ORA_DBA group), set ORACLE_HOME and ORACLE_SID environment variables, then login as:
sqlplus / as sysdba
You should get logged in without having to provide a password.