-- Example of a profile
CREATE PROFILE DBSTAR_SELECT 
LIMIT SESSIONS_PER_USER    2
CPU_PER_SESSION            DEFAULT
CPU_PER_CALL               3000 
CONNECT_TIME               60 
LOGICAL_READS_PER_SESSION  DEFAULT 
LOGICAL_READS_PER_CALL     DEFAULT
COMPOSITE_LIMIT            DEFAULT
; 

alter system set resource_limit = true
;

and also change the init.ora parm: resource_limit


-- alter a profile
alter profile DBSTAR_SELECT limit SESSIONS_PER_USER unlimited
/