DB2 FOR LUW / DB2FORLUW / 970 - DB2

In certain environment, cost for fetching massive rows from 
remote server is over-cost, while execution of a remote 
statement multi-times is under-cost. As a result, IFS chooses a 
NLJN which fetches remote data for multi-times, instead of 
choosing the HSJN which fetches all data of a remote table at 
one time, and the performance could be bad with the NLJN.

Problem Description: 
SERVER OPTIONS NEED TO BE ADDED TO ADJUST COST ESTIMATION FOR 
FETCHING DATA FROM REMOTE SERVER IN CERTAIN ENVIRONMENT 
 
Problem Summary: 
In certain environment, cost for fetching massive rows from 
 
remote server is over-cost, while execution of a remote 
statement multi-times is under-cost. As a result, IFS chooses a 
NLJN which fetches remote data for multi-times, instead of 
choosing the HSJN which fetches all data of a remote table at 
one time, and the performance could be bad with the NLJN.

Use plan hints, explicit selectivity, stats views to force the 
HSJN plan.

DB2 Version 9.7 Fix Pack 4 for Linux, UNIX, and Windows
 DB2 Version 9.7 Fix Pack 5 for Linux, UNIX, and Windows
 DB2 Version 9.7 Fix Pack 6 for Linux, UNIX, and Windows
 DB2 Version 9.7 Fix Pack 7 for Linux, UNIX, and Windows
 DB2 Version 9.7 Fix Pack 8 for Linux, UNIX, and Windows
 DB2 Version 9.7 Fix Pack 9 for Linux, UNIX, and Windows
 DB2 Version 9.7 Fix Pack 9a for Linux, UNIX, and Windows
 DB2 Version 9.7 Fix Pack 10 for Linux, UNIX, and Windows
 

Problem is first fixed in Version 9.7 Fixpack 4

Use plan hints, explicit selectivity, stats views to force the 
HSJN plan.

Datum - Problem gemeldet    :
Datum - Problem geschlossen :
Datum - der letzten Änderung:

20.08.2010
28.02.2011
28.02.2011

9.7.FP4