Did you check which query engine advices the indexes?
I assume these advices are made from queries running with the CQE.
CQE only uses estimated information to determine access paths, but the real
data may be different and in this way the created index may not used.
SQE is more accurate, i.e. the collected statistics information (composition
of the "real" data) is checked and used for index advice and building the
access plan.
If a lot of your queries are using the CQE, first try to move them to SQE
and then check the index advices.
... BTW the White Paper for "Indexing and Statistics Strategies" was
recently updated:
https://www-304.ibm.com/partnerworld/wps/servlet/ContentHandler/stg_ast_sys_
wp_db2_i_indexing_methods_strategies
Mit freundlichen Grüßen / Best regards
Birgitta Hauser
"Shoot for the moon, even if you miss, you'll land among the stars." (Les
Brown)
"If you think education is expensive, try ignorance." (Derek Bok)
"What is worse than training your staff and losing them? Not training them
and keeping them!"
-----Ursprüngliche Nachricht-----
Von: midrange-l-bounces@xxxxxxxxxxxx
[mailto:midrange-l-bounces@xxxxxxxxxxxx] Im Auftrag von Wyatt, Chris
(FGWA-IL)
Gesendet: Wednesday, 10. August 2011 20:42
An: MIDRANGE-L@xxxxxxxxxxxx
Betreff: Index advisor...
This is not the end of the world but it's bugging me...
Periodically, I review the "Condensed Index Advice" in Navigator and build
indexes if they've been advised a lot and/or have a long creation time.
On many occasions, I've built an index straight from the Advice tool only to
have the system continue to advise building that same index. Same key, same
Index Type, same everything.
Any thoughts on why this is happening?
Thank you!
Chris Wyatt
ERP Developer/Analyst
FleetwoodGoldcoWyard
A Barry-Wehmiller Company
(630) 759-6800 x301
midrange.com
