A customer recently upgraded his outdated iSeries OS to version 5.2.
Since then, some queries seem to run far longer than before. This is why they consulted
a performance expert of IBM.
After talking for about 30 minutes with this guy, I must admit that I'm still
far too prejudiced about the RDBMS (DB2/400) of the iSeries. Appartenly lack of knowledge
is one of the major things that cause us to say "this software is worthless", "how
is possible that you cannot do this" or similar things . It seems the 'thing'
can do more than I expected and works better than I could imagine. But of course,
you need to know some basics of the system (which I lack).
It's really a shame that I didn't think somewhat further. I'm one of those people
who like VB. (And yes, I use best practices, I follow naming conventions, create classes
(yep, facade, business and data access logic stuff)). But indeed, VB has a bad name.
However, if you use the tool in a good way, you can do great things with it in a rather
short time...
Only a few months ago I had several discussions with Delphi-adepts (who were
trying to do some VB) about this. I countered every statement they made about things
they thought that are impossible to do in VB. Never did I leave a change to say to
them that you have to learn the platform/tool before trying to make it work. But today,
I realized that I made that mistake myself with DB2/400... Yet another lesson learned...
PS. Apparently IBM has some tight release schedules too: they released version 5.2
of OS/400 without a new database engine. The new database engine was released as PTF
(similar to a Microsoft Service Pack) later on...