Database Reference
In-Depth Information
' - '||lower(substr(s.program,length(s.program)-4,4) ) ) "Username",
decode(px.qcinst_id,NULL, 'QC', '(Slave)') "QC/Slave" ,
to_char( px.server_set) server_set,
to_char(s.sid) "SID",
decode(px.qcinst_id, NULL ,to_char(s.sid) ,px.qcsid) "QC SID",
px.req_degree "Requested DOP",
px.degree "Actual DOP"
from
v$px_session px,
v$session s
where
px.sid=s.sid (+)
and
px.serial#=s.serial#
order by 5 , 1 desc
/
Username QC/Slave ServerSet SID QC SID Requested DOP Actual DOP
------------ ---------- ---------- ------ ------ ------------- ----------
RS QC 12376 12376
- p015 (Slave) 2 10756 12376 8 8
- p014 (Slave) 2 11295 12376 8 8
- p013 (Slave) 2 10211 12376 8 8
- p012 (Slave) 2 9699 12376 8 8
- p011 (Slave) 2 9147 12376 8 8
- p010 (Slave) 2 7535 12376 8 8
- p009 (Slave) 2 8609 12376 8 8
- p008 (Slave) 2 8071 12376 8 8
- p007 (Slave) 1 6474 12376 8 8
- p006 (Slave) 1 7012 12376 8 8
- p005 (Slave) 1 5403 12376 8 8
- p004 (Slave) 1 5928 12376 8 8
- p003 (Slave) 1 4847 12376 8 8
- p002 (Slave) 1 4325 12376 8 8
- p001 (Slave) 1 3787 12376 8 8
- p000 (Slave) 1 2716 12376 8 8
In Figure
12-2
, a SQL execution with a requested DOP set to 4 is shown. There are four processes acting as
producers and four acting as consumers, and a QC receives the row pieces from consumers. This data flow operation
shows that row pieces are distributed from one PX server set to another PX server set.
