| PARALLEL hint is not working in 11g. [message #616807] |
Fri, 20 June 2014 14:19  |
M. Salman Sabir
Messages: 5
Registered: March 2002
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Junior Member |
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SQL stmt:
SELECT /*+ PARALLEL(r) */
r.c1 , r.c2
FROM table1 r
--> Table1 has 44 million records.
Explain Plan:
SELECT STATEMENT, GOAL = ALL_ROWS Cost=300698 Cardinality=44703140 Bytes=447031400
TABLE ACCESS FULL Object owner=axe Object name=Table1 Cost=300698 Cardinality=44703140 Bytes=447031400
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| Re: PARALLEL hint is not working in 11g. [message #616849 is a reply to message #616816] |
Sat, 21 June 2014 10:04  |
John Watson
Messages: 8931
Registered: January 2010
Location: Global Village
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Senior Member |
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There is nothing wring with your syntax, but there are many reasons why you might not get parallel execution in 11.2.x. Also, what you say is the output of EXPLAIN PLAN is all wrong for 11.2. Please will you show what is happening, by using copy/paste from a SQL*Plus session, and enclose the result in code tags. Like this:
c:\users\john>
c:\users\john>sqlplus scott/tiger
SQL*Plus: Release 11.2.0.3.0 Production on Sat Jun 21 16:03:02 2014
Copyright (c) 1982, 2011, Oracle. All rights reserved.
Connected to:
Oracle Database 11g Enterprise Edition Release 11.2.0.3.0 - 64bit Production
With the Partitioning, Data Mining and Real Application Testing options
orcla> set autotrace on explain
orcla> select /*+ parallel */ count(ename) from emp;
COUNT(ENAME)
------------
14
Execution Plan
----------------------------------------------------------
Plan hash value: 2810914317
------------------------------------------------------------------------------------------------------------
| Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time | TQ |IN-OUT| PQ Distr
------------------------------------------------------------------------------------------------------------
| 0 | SELECT STATEMENT | | 1 | 6 | 2 (0)| 00:00:01 | | |
| 1 | SORT AGGREGATE | | 1 | 6 | | | | |
| 2 | PX COORDINATOR | | | | | | | |
| 3 | PX SEND QC (RANDOM) | :TQ10000 | 1 | 6 | | | Q1,00 | P->S | QC (RAND
| 4 | SORT AGGREGATE | | 1 | 6 | | | Q1,00 | PCWP |
| 5 | PX BLOCK ITERATOR | | 14 | 84 | 2 (0)| 00:00:01 | Q1,00 | PCWC |
| 6 | TABLE ACCESS FULL| EMP | 14 | 84 | 2 (0)| 00:00:01 | Q1,00 | PCWP |
------------------------------------------------------------------------------------------------------------
Note
-----
- automatic DOP: skipped because of IO calibrate statistics are missing
orcla> |
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