DB2 FOR LUW / DB2FORLUW / A10 - DB2

Spatial queries that invoke a spatial constructor a large number 
of times result in many direct write and read operations which 
may make performance unaccepable, especially for online 
applications. 
 
A particularly common application is finding what polygon a 
point is in given a table of polygons and a table with 
locations. 
 
In this example, there is a table of zipcode polygons and a 
table of customers with the location in latitude and longitude: 
 
select c.cust_name, z.zip 
from customers AS c 
   ,zippoly AS z 
where 
db2gse.st_contains(z.shape,db2gse.st_point(longitude,latitude,1) 
) = 1

**************************************************************** 
* USERS AFFECTED:                                              * 
* DB2 Spatial Extender                                         * 
**************************************************************** 
* PROBLEM DESCRIPTION:                                         * 
* Poor performance of spatial queries due to excessive direct  * 
* write and direct read operations.                            * 
*                                                              * 
* This problem can be identified by at db2batch or snapshot    * 
* information and checking the number of direct write and      * 
* direct read operations that occurred in evaluating the       * 
* query.  If the number of direct write and direct read        * 
* operations are more than twice the number of table rows      * 
* processed in evaluating the query, this is the likely cause. * 
*                                                              * 
* The product fix will eliminate most of the direct operations * 
* in most cases, especially when spatial point data is being   * 
* queried.                                                     * 
**************************************************************** 
* RECOMMENDATION:                                              * 
* Install V10.1 Fixpack 2                                      * 
****************************************************************

DB2 Version 10.1 Fix Pack 2 for Linux, UNIX, and Windows
 DB2 Version 10.1 Fix Pack 3 for Linux, UNIX, and Windows
 DB2 Version 10.1 Fix Pack 4 for Linux, UNIX, and Windows
 DB2 Version 10.1 Fix Pack 3a for Linux, UNIX, and Windows
 DB2 Version 10.1 Fix Pack 6 for Linux, UNIX, and Windows
 

Install V10.1 Fixpack 2

not known / see Local fix

Date  - problem reported    :
Date  - problem closed      :
Date  - last modified       :

07.08.2012
02.01.2013
02.01.2013