Re: Move 4 to 5 or 4 to 7

Alastair Kimbell <al@ackone.demon.co.uk> wrote: : Hi there :I'm trying to decide wether to upgrade from 4 to 5 or 4 to 7 (SE) Evaluate going to Online Workgroup Server as well. It's a very good product, and it's where things are happening. :If you get any info I would be most interested. If I find any out I'll :contact you. Just post in c.d.i. :What I have found so far is that 7 has a new cost based optimiser that :can :speed up queries : more sophisticated than the old update statistics in :that it takes into :account data distribution etc This is only an advantage if you have optimiser based problems now. We had and got a at least a 100 to 1 performance enhancement on one special type of query (a join that started with the wrong table). However to make all other queries go right we also had to play a lot with update statistics. We even had to do distributions for fields not part of any index. If you get problems you should test different update statistics strategies for every field referenced in the where clause, not only those that are part of an index. In version 5 we simply did an update statistics and everything but this one problem query ran fine (we have of course done quite some work on optimizing our sql statements). The real lesson from this however is that with 7 you can solve problems that are hard and sometimes nearly impossible to solve with any earlier version. :7 will also be supported for longer than 5 (or 4 in my case which is :currently unsupported by informix) :Also moving directly to 7 means you don't have to migrate via 5 & 6 etc. : :I hope this useful, If you get any better info please let me know. :Many thanks Even with the above problems with update statistics I would still go with the latest version. It's an issue of functionality, support and bugfixes. I don't spend my time on problems that are allready solved. Time is virtually allways more valuable than any other thing. Nils.Myklebust@idg.no NM Data AS, P.O.Box 9090 Gronland, N-0133 Oslo, Norway My opinions are those of my company The Informix FAQ is at http://www.iiug.org