Oracle Database Discussions

Good afternoon,

I am learning Oracle 11gR2. When I issue the query (on a Windows system):

select addr, pid, spid , pname, username from v$process;

I get the following output (abbreviated):

ADDR            PID SPID                     PNAME USERNAME
-------- ---------- ------------------------ ----- ---------------
2F073324          1
2F073E2C          2 556                      PMON  SYSTEM
2F074934          3 564                      VKTM  SYSTEM
2F07543C          4 488                      GEN0  SYSTEM
2F075F44          5 484                      DIAG  SYSTEM
2F076A4C          6 480                      DBRM  SYSTEM
...
...
2F0825D4         23 6948                     W000  SYSTEM
2F0830DC         24 3920                           SYSTEM
2F083BE4         25 3148                     Q002  SYSTEM
2F0846EC         26 3392                           SYSTEM
2F0851F4         27 3232                     CJQ0  SYSTEM

I noticed that SPID, PNAME and USERNAME are null for the first row.

The question is: Why are the values for the first row null and what does it mean ?

Secondary question: I noticed that some PNAME values are null in other rows. Are those undocumented Oracle processes or is it because of a different reason ?

Thank you for your help,

John.