Wrong Results when query is executed in parallel (Doc ID 1179661.1)

Last updated on MARCH 27, 2014

Applies to:

Oracle Server - Enterprise Edition - Version: 11.2.0.1 to 11.2.0.2.0 - Release: 11.2 to 11.2
Information in this document applies to any platform.

Symptoms


Simple query produces inconsistent results when one of Join tables is in PARALLEL 4.
When parallel is disabled, query produces consistent results.


SQL> SELECT
SUM (vector_month_proj_factor)
FROM j5102_media.j5102_rx PARTITION (m200804) a, j5102_media.j5102_doi b
WHERE a.market_id = 26
AND a.market_id = b.market_id
AND a.product_id = b.product_id 2 3 4 5 6
7 ;

SUM(VECTOR_MONTH_PROJ_FACTOR)
-----------------------------
18482.6649 --->wrong results


When query executed is serial or using any of these

SQL> ALTER SESSION SET "_hash_join_enabled"=FALSE;
or
alter session set optimizer_features_enable ='10.2.0.4';


Session altered.


SQL> SELECT
SUM (vector_month_proj_factor)
FROM j5102_media.j5102_rx PARTITION (m200804) a, j5102_media.j5102_doi b
WHERE a.market_id = 26
AND a.market_id = b.market_id
AND a.product_id = b.product_id 2 3 4 5 6 ;

SUM(VECTOR_MONTH_PROJ_FACTOR)
-----------------------------
50410.1079 --->correct results


Cause

Sign In with your My Oracle Support account

Don't have a My Oracle Support account? Click to get started

My Oracle Support provides customers with access to over a
Million Knowledge Articles and hundreds of Community platforms