In this Article, i explain how to limit access to database for only one user per schema which mean one concurrent user per schema.
Resource_limit should set to True
SQL> show parameter resource
NAME TYPE VALUE
resource_limit boolean TURE
resource_manager_plan string
After change this parameter Bounce database.
Connect to database using sysdba privileges
sqlplus / as sysdba
create profile Only_one_user limit sessions_per_user 1;
Create New User/modify old one depend on what you want:
create user test identified by test profile Only_one_user;
grant connect to test;
Now Try to connect to this user using more than one terminal, if you did you will receive error
ORA-02391: exceeded simultaneous SESSIONS_PER_USER limit