Why is this app's performance so bad?

It was an SQL interactive inquiry reading about 500 records from three
tables. It ran fine on my local system but dragged on the customer's
system.

Naturally, I assumed I'd done something idiotic or there was a data issue
I'd missed. The source code and data was identical on test and production
but I kept fiddling to no avail...I ran dozens of tests. And then I ran
DSPDBR.

Aha--DSPDBR showed I'd had built indexes on my system, thanks to Index
Advisor, but I'd (foolishly) thought SQL would build the needed MTI's on
the customer's system. After uploading and compiling my source members (I
script everything, even index builds ), I was relieved to see subsecond
response immediately. Indexes work and they make a difference even in
small applications.

The moral of the story: use Index Advisor. Or use DSPSBR first. Can't
figure out which.