Hello,
I am trying to understand the following run..
sqlplus <user>/<pwd>@db
SQL*Plus: Release 11.2.0.1.0 Production on Fri Dec 16 01:25:38 2016
Copyright (c) 1982, 2010, Oracle. All rights reserved.
Connected to:
Oracle Database 11g Enterprise Edition Release 11.2.0.3.0 - 64bit Production
With the Partitioning, Real Application Clusters, Automatic Storage
Management, OLAP,
Data Mining and Real Application Testing options
SQL> select * from v$mystat where rownum <= 1;
SID STATISTIC# VALUE
---------- ---------- ----------
278 0 0
SQL>
SQL>
SQL> alter session force parallel DDL;
Session altered.
SQL> alter session force parallel DML;
Session altered.
SQL> alter session force parallel query;
Session altered.
SQL>
SQL> create table t15 as select * from dba_objects union all select * from
dba_objects;
^C
At this point, I had to stop the process as it created 289 sessions and was
still running..
I made some changes and re-ran..
sqlplus <user>/<pwd>@db
SQL*Plus: Release 11.2.0.1.0 Production on Fri Dec 16 01:29:34 2016
Copyright (c) 1982, 2010, Oracle. All rights reserved.
Connected to:
Oracle Database 11g Enterprise Edition Release 11.2.0.3.0 - 64bit Production
With the Partitioning, Real Application Clusters, Automatic Storage
Management, OLAP,
Data Mining and Real Application Testing options
SQL> alter session force parallel DDL;
Session altered.
SQL> alter session force parallel DML;
Session altered.
SQL> alter session force parallel query;
Session altered.
SQL>
SQL> set timing on
SQL>
SQL> select * from v$mystat where rownum <= 1;
SID STATISTIC# VALUE
---------- ---------- ----------
278 0 0
Elapsed: 00:00:00.50
SQL>
SQL> create */*+ parallel(4) */* table t15 as select * from dba_objects
union all select * from dba_objects;
Table created.
Elapsed: 00:00:08.02
The highlighted part is the only changed I made, but I cannot explain why
this worked with no additional sessions.. I have never seen this syntax
mentioned anywhere but a casual try worked.
Does anyone know how this works ?
Rgds,
Gokul
