v$session and v$process are two very useful dynamic views, but I always confused with the following fields in the two views
according to Oracle® Database Reference 11g Release 1 (11.1) B28320-03
v$session.process = Operating system client process ID
v$process.SPID = Operating system process identifier
v$process.PID = Oracle process identifier
As I understand the manual, if I join the two view with v$session.paddr = v$process.addr, the value of
$session.process and v$process.SPID should be the same and represet the OS process id. However, they are not the same and none of them are displayed in the result of the Linux commads
ps -fe|grep <v$process.SPID>
ps -fe|grep <v$session.process>
$process.PID is also a mystery. We have sid and serial#. Why is the Oracle process id, and how and when to use it?
Many thanks