It not only advices indexes for the query, but also indexes that might help
the statistics manager to gather the information about the data composition
faster.
Also the advised indexes are determined based on algorithms while finally
the decision is made in composition with the (real) data, i.e. the
information gathered by the statistics manager.
Mit freundlichen Grüßen / Best regards
Birgitta Hauser
Modernization ? Education ? Consulting on IBM i
Database and Software Architect
IBM Champion since 2020
"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!"
"Train people well enough so they can leave, treat them well enough so they
don't want to. " (Richard Branson)
"Learning is experience ? everything else is only information!" (Albert
Einstein)
-----Original Message-----
From: MIDRANGE-L <midrange-l-bounces@xxxxxxxxxxxxxxxxxx> On Behalf Of David
Gibbs via MIDRANGE-L
Sent: Thursday, 12 February 2026 15:39
To: midrange-l@xxxxxxxxxxxxxxxxxx
Cc: David Gibbs <david@xxxxxxxxxxxx>
Subject: RSS Visual Explain index advisor
Folks:
I'm a bit confused ... I've got a query that performs some joins and record
selections.
I ran it through visual explain (VE) and reviewed the indexes it
recommended.
I created those indexes and re-ran VE ... It no longer recommended those
indexes, but the diagram it showed remained the same. It appears that it
didn't actually USE the indexes it previously recommended.
When I viewed the indexes considered, the newly created indexes had a reason
code of 4 because the cost to use the access path was higher than the cost
of the chosen access path.
Any idea why it would recommend access paths and then disregard them once
they exist?
Thanks!
david
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