I have created a new user 'u' using my 'security_admin' role, and assigned role 'r' (which already has some select/usage permission on few tables) to the user. Now I want add more permissions to the role. I have ran below statement:
grant select on all tables in schema db_name.schema_name to role r;
The above statement gives necessary permission to the user 'u', i have checked with show grants to role r statement. However the granted permission is valid only for one day, the next day the user does not have the permission that is granted using above statement. It keeps happening for sometime. I do not know what the problem is. I do not have any automated SQL script to recreate users & grants daily.