Oracle PL/SQL Tutorial/System Tables Data Dictionary/V SESSION
30. Blocked-session details
<source lang="sql">
SQL> SQL> select sid, blocking_session, username, blocking_session_status,
2 program, event, seconds_in_wait 3 from v$session 4 where blocking_session_status = "VALID";
no rows selected SQL></source>
30. Dynamic Performance Views: V$SESSION contains information about each connected user or process in the database
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SQL> SQL> select sid, serial#, username, program from v$session
2 where username = "HR";
no rows selected</source>
30. Users in rollback segments
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SQL> REM SQL> column rr heading "RB Segment" format a18 SQL> column us heading "Username" format a15 SQL> column os heading "OS User" format a10 SQL> column te heading "Terminal" format a10 SQL> select R.Name rr,
2 nvl(S.Username,"no transaction") us, 3 S.Osuser os, 4 S.Terminal te 5 from V$LOCK L, V$SESSION S, V$ROLLNAME R 6 where L.Sid = S.Sid(+) 7 and trunc(L.Id1/65536) = R.USN 8 and L.Type = "TX" 9 and L.Lmode = 6 10 order by R.Name 11 /
SQL></source>