Re: Move 4 to 5 or 4 to 7

Nils Myklebust wrote: > 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 Many thanks for the info It is starting to look like 7 is the way to. Do you anything about issues to do with recompiling esql/c from version 4 to version 5 or 7 (I have very little c experience) probably enough to do a recompile of the main source if everythnig goes right !!! Thanks in advance A.Kimbell al@ackone.demon.co.uk