Re: Online 7.x on IBM uni-processor

Nils Myklebust wrote: > > David Kerslake <daveanne@ihug.co.nz> wrote: > > :We are running Informix systems on IBM RS6000s under AIX 4.2. We > have to > :upgrade to Informix DSA v7.x to take advantage of the latest release > of > :our application. > : > :We have heard that DSA, written for multi-processors, runs slower on > a > :uni-processor (which is what we have). Has anyone any information on > :any potential performance degradation? > > From post's here and some use of the 7.x engines it seems like you > should be able to get more or less the same performance as with 5.x > under the following conditions: > - A reasonably new version of the 7.x engine > - The latest version of the OS > - Enough memory (may require more than the 5.x engine) > - Tuning the OS appropriately > - Tuning the engine appropriately > > The last is what requires most work of course and is in this sence > most important. You have to realy study the administration manuals and > might want to go to a curse to learn more about it. I've seen a number of sites upgrade from 5 to 7 and see a drop in performance. However, the cause at most of these sites was poor application code (I AM wearing a flack jacket :-} I know this is a sore point with programmers :). The main area was PREPARE and DECLARE. This seems to have a far bigger impact in 7 than in 5. Once these sites PREPAREd and DECLAREd all cursors, performance was normally better than in 5. Recommendation: Prepare your application before you prepare to upgrade. Cheers, -- Mark. +----------------------------------------------------------+-----------+ |Mark D. Stock - Informix SA http://www.informix.com |//////// /| |mailto:mdstock@informix.com FAQ http://www.iiug.org |///// / //| | +-----------------------------------+//// / ///| | Tel: +27 11 807 0313 |If it's slow, the users complain. |/// / ////| | Fax: +27 11 807 2594 |If it's fast, the users keep quiet.|// / /////| |Cell: +27 83 250 2325 |Therefore, "No news: travels fast"!|/ ////////| +----------------------+-----------------------------------+-----------+