Database Reference
In-Depth Information
You can verify that parallel DML has been enabled for your session via:
EODA@ORA12CR1> select pdml_enabled from v$session where sid = sys_context('userenv','sid');
PDM
---
YES
The fact that the table is “parallel” is not sufficient, as it was for parallel query. The reasoning behind the need
to explicitly enable PDML in your session is the fact that PDML has certain limitations associated with it, which I list
after this example.
In the same session, we do a bulk
UPDATE
that, because the table is “parallel enabled,” will in fact be done in parallel:
EODA@ORA12CR1> update big_table set status = 'done';
In the other session, we'll join
V$SESSION
to
V$TRANSACTION
to show the active sessions for our PDML operation,
as well as their independent transaction information:
EODA@ORA12CR1> select a.sid, a.program, b.start_time, b.used_ublk,
2 b.xidusn ||'.'|| b.xidslot || '.' || b.xidsqn trans_id
3 from v$session a, v$transaction b
4 where a.taddr = b.addr
5 and a.sid in ( select sid
6 from v$px_session
7 where qcsid = 258)
8 order by sid
9 /
SID PROGRAM START_TIME USED_UBLK TRANS_ID
---------- ------------------------------ -------------------- ---------- ---------------
11 oracle@heera07 (P00B) 02/25/14 14:10:17 13985 26.32.15
12 oracle@heera07 (P000) 02/25/14 14:10:17 1 70.16.6
21 oracle@heera07 (P00F) 02/25/14 14:10:17 13559 20.18.37
23 oracle@heera07 (P007) 02/25/14 14:10:17 1 12.3.62
26 oracle@heera07 (P004) 02/25/14 14:10:17 1 33.4.11
95 oracle@heera07 (P005) 02/25/14 14:10:17 1 48.15.10
97 oracle@heera07 (P00C) 02/25/14 14:10:17 12676 9.5.1730
103 oracle@heera07 (P008) 02/25/14 14:10:17 14434 44.32.10
105 oracle@heera07 (P001) 02/25/14 14:10:17 1 64.0.9
169 oracle@heera07 (P002) 02/25/14 14:10:17 1 34.19.11
176 oracle@heera07 (P00D) 02/25/14 14:10:17 14621 4.22.1739
177 oracle@heera07 (P006) 02/25/14 14:10:17 1 74.14.6
191 oracle@heera07 (P009) 02/25/14 14:10:17 13070 54.11.10
258 sqlplus@heera07 (TNS V1-V3) 02/25/14 14:10:17 1 59.8.12
261 oracle@heera07 (P00A) 02/25/14 14:10:17 13521 7.13.1748
263 oracle@heera07 (P00E) 02/25/14 14:10:17 12186 14.23.76
267 oracle@heera07 (P003) 02/25/14 14:10:17 1 28.23.19
17 rows selected.
