V$PX_SESSION the sessions running parallel execution
What are parallel sessions ? select qcsid , count( 1 ) from v$px_session group by qcsid ; QCSID field means Query Coordinator, main session that coordinates slave sessions. Details.... COL USERNAME FOR A16 HEADING 'Username' COL MACHINE FOR A24 HEADING 'Machine' COL PROGRAM FOR A33 HEADING 'Program' COL OSUSER FOR A14 HEADING 'OS | User' COL QC FOR A3 ALTER SESSION SET NLS_DATE_FORMAT= 'DD-MON-YYYY HH24:MI:SS' ; SET LIN 150 SET PAGES 103 compute sum LABEL 'Total Memory' of memory_mb on report compute count LABEL 'Count Parallel' of sid on report undefine SID break on report select s .sid,decode( pxs .sid, pxs . qcsid , 'X' ,NULL) QC , s . username , s . osuser , p. spid "OS PID" , s .program, s . machine , status , s . logon_time ,round(p. PGA_ALLOC_MEM / 1024 / 1024 ) memory_mb from v$session s , v$process p, v$px_