Re: Upgrade from 5 to 7

In article <335CEB26.751A@ana.med.uni-muenchen.de>, Richard says... > >John F. Tosh wrote: >> >> I am currently creating a document to support my reasoning for upgrading >> our Informix database from version 5 to 7 [...] > >Why is version 5 not good enough for you any more? > >You should seriously ask yourself that question. We did, and found >that upgrading really wasn't worth all the hassle for several reasons: > >1) Online 5 has been running stable with satisfactory performance > on our single-processor system for years. >2) At several occasions, we asked Informix reps whether we could expect > any performance benefits from version 7 on our single-processor > machine. The answer was always that there would most likely be > no noticeable improvement. > (I expect an outcry from many people here. Ok, you are probably > right, version 7 can be tuned to run faster than version 5, but > performance has been good enough so far, so why bother?) >3) We have tons of legacy code written in I4GL 4.1. All this code > would have to be re-compiled with I4GL 6.x and thoroughly tested, > since there ARE incompatibilities. The time required to do this > would be several weeks, depending on how many people we could > spare. No way with our present staffing. > Without recompilation, we would suffer serious performance hits > by having to go through the "relay module". >4) The only advantage of 7.2 I could really use are the new backup > tools. But I've learned to live with what I got. >5) Very important: Version 5 is still supported and continues to > be improved by Informix. We are presently at Online 5.07, and > I've already heard of higher version numbers on other platforms. > So version 5 is not a dead product. > >I'm sure there might be many reasons to upgrade, but it depends on >your individual situation whether it's really worth it. > >Regards, Richard >-- >+--------------------------+------------------------------------------+ >| Dr. Richard Spitz | INTERNET: spitz@ana.med.uni-muenchen.de | >| EDV-Gruppe Anaesthesie | Tel : +49-89-7095-3413 | >| Klinikum Grosshadern | FAX : +49-89-7095-8886 | >| 81366 Munich, Germany | | >+--------------------------+------------------------------------------+ We went thru this . Richard is absolutely right pointing out those points. If you have significant amount of applications, the transition can be very costly and painful. You shall have significant performance advantages with DSS applications if you have sufficient number of disks to utilise fragmentation, multiple CPUs to have decent parallelization, and preferably whole machine should be dedicated to Informix Engine . With OLTP systems .. well I have not seen massive imrovements, but even those I've seen - you know, I am not sure whether it was because of Inf 7 or because we had to use much more powerful box, frankly. Sometimes performance was even worse than on 5.x My estimate is in OLTP environment CPU time and memory consumption have increased by at least by 20 per cent. I sincerely hoped that 7.x would be less buggy, but it was wrong assumtion. Hope it helps (or is it ?) Cheers, ILya The opinion is strictly personal.