After the Oracle database is created, the System user sys or sysdba cannot log on to sqlplus.

After the Oracle database is created, the System user sys or sysdba cannot log on to sqlplus. The system user sys or sysdba cannot log on to sqlplus to run-> cmd. Enter sqlplus/nolog and press Enter. Enter conn/as sysdba and press Enter. Drop user test cascade; (Note: if a user test exists, all information of the user is deleted first .) Create user test identified by test; grant resource, connect, exp_full_database, imp_full_database to test; (grant the database resource, connection, export, import authorization to the test user) grant unlimited tablespace to test; (The tablespace is not restricted and authorized to the test user)