Re: informix SE very slow

oss96@batelco.com.bh wrote: :hi there, : :informix SE 7. is very very slow on dec axp 2000 comparing with pentium :166, one of my customer was running a test to chech the performance with :a small report, it takes 3 min. on pentium 166. and 55 min on dec axp :2000 with dec unix 4.0b. is any suggestion. As it's an SE engine there isn't much tuning to do at the engine level appart possibly from OS tuning for I/O buffers and similar things. One thing might be the indexing. In situations like this you have to use "set explain on" to see what's realy going on. If the indexes are there, but the right ones aren't used you have to start doing update statistics properly using medium and high as appropriate. This was realy simple on SE 5.x, but became quite involved with SE 7.x. As a compensation SE 5.x sometimes did joins the wrong way and there wasn't much one could do appart from resorting to tricks in the SQL code. In 7.x update statistics can usually remedy such problems when applied well. 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