That's the expected behavior Ralberto. The SID values are reused during the life of the instance but SERIAL# is extended each time. Therefore it is perfectly natural to see sessions with the same value of SERIAL#. It's the (SID, SERIAL#) combination that you expect to be unique during the life of the instance. Kindest regards, Iggy -- Iggy FernandezEmail: iggy_fernandez@hotmail.comBlog: So Many Manuals So Little TimeAuthor of Beginning Oracle Database 11g AdministrationEditor of the NoCOUG Journal > From: ralberto.hernandez.ext@xxxxxxxxxxxxxxxxxxx > I have a question for your all, i don´t understand because in v$session > we have many sessions (BMC/REMEDY) with different sid and same serial#. -- //www.freelists.org/webpage/oracle-l