Re: Performance tuning

Yes indeed, the art vs. science aspect is exactly why I reached out to the community.  There are parts of the IBM i development environment where I consider my competent, and others where I don't, and tuning is definitely one of those areas where I'm not as certain.
Application review is definitely an ongoing issue.  We have a number of areas where we already know we're going to have to do some work.  But it's best to have a plan when going to the CIO - something a little more concrete than "we're going to have to fix everything".  :)

On 11/30/2018 4:22 PM, Jim Oberholtzer wrote:

Until it's not.......

If you have heavy SQL, them that setting can, not always certainly, and usually does, bollox things up. It forces the optimizer to run for every query. Sometimes it'll do a table scan, other times it'll build an index. It may or may not use existing index objects.

Mean time you're sitting there trying to understand why things run differently every day.

Bottom line is, performance is as much art as science, and a solid understanding of the application is a good starting point.

Jim Oberholtzer
Agile Technology Architects

On Nov 30, 2018, at 12:19 PM, Roger Harman <roger.harman@xxxxxxxxxxx> wrote:

When I had that responsibility, I just set QPFRADJ to '3' and was a happy camper. Figured the machine was smart enough.

Roger Harman
COMMON Certified Application Developer - ILE RPG on IBM i on Power