Coexistence Logical/Index rebuild recommendations

b_gilmore

Well Known Member
Hello all:

Have a question I've been trying to answer for some time.

By now everyone has heard about the performance improvement you can sometimes
achieve by simply regenerating the OneWorld logicals out on the AS/400 for
certain files with mucho records.

This procedure works fine for OneWorld only installations but what about a
Coexistence installation?

The end result of a coex install is the World logicals proxying for the
OneWorld indexes in most cases (e.g. F0101LA stands in for F0101_1). In the
event that OneWorld has more indices defines for the file than World, the
install just adds the OW index to the end of the list. So for example you
could end up with the following logicals on a file:

F0101 Physical
[World Logicals generated during World install]
F0101LA
F0101LB
F0101LC
F0101LD
[OneWorld Indexes during Coexist install]
F0101_5
F0101_6

The quandry here is what to do if you want to rebuild the indices on F0101 in
a coexistence situation? If you simply select "Generate Indexes" from OMW,
you'll end up with
F0101 Physical
F0101LA
F0101LB
F0101LC
F0101LD
F0101_1
F0101_2
F0101_3
F0101_4
F0101_5
F0101_6

My understanding is that the structure of the World *LA logical is identical
to the *_1 OneWorld Index and so on. So would this be a performance hit
instead of a possible improvement especially during updates to the file where
it has to propagate all new records to more indices than necessary?

Has anyone developed a strategy for this situation? I'd love to hear about
it.

Regards,
Bruce Gilmore
 
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