RE: SYSIXADV Question.

Surely sites of this site elsewhere in the iSeries world have one or more 
people who are conversant with this sort of stuff?

I work for a company that specializes in SQL performance tooling on the
System i (Centerfield Technology).
Unfortunately, what I've observed in talking to System i shops is that
tuning SQL performance is often treated as implementing proper security on
the system - techies only do it when they must.  
For security it may be that SOX or other law forces them, or some disaster
forces them (theft, inadvertent corruption of data, merging with other
entities and thus exposing your data).
With SQL it's when finally customer complains that a web page or a record
won't come up "forever" or batch job passes its runtime window and
additional hardware isn't helping, or "application works fine on test box
but crawls on production box".
I call these "house is on fire" situations.  When house is on fire, you want
to call a fireman and have him take care of it, but you don't want to mess
with it yourself.

Anyway, to stop venting... if folks were proactive rather than reactive and
put some thought into proper SQL tuning practices they could be champions in
their shops rather than clean-up crew. Often a single tuning effort can
provide tremendous performance gains, provided you find "right knobs" to
turn.

On the other hand, if everyone was so conscientious, what would vendors and
consultants do :)

BTW, a good start to building expertise in SQL performance tuning is Query
Optimization class IBM offers all around the world.  It's usually about 3
days long and features some excellent instructors.

Elvis

Celebrating 10-Years of SQL Performance Excellence