Re: Update Statistics: Tell me the truth

From: patricia_br@my-deja.com > >Update statistics is kinda of an obscure subject with Informix. Oh? >I can never get a straight answer on the correct way to run it and (most >important) WHY ? Besides, there are some optimizer problems with version >7.3x and as far as I know, what the book recommends is not quite valid >anymore. >I have two questions: >1 - Based on your experience, what is the real recommendation for Update >statistics ? (version 7.3x up?) >2 - Is it true that if you have OPTCOMIND set up to 0 you do not have to >run update statistics HIGH and MEDIUM ? Here's a straight answer: it all depends. * If your data is relatively static, you don't need to run it often. * if your data is relatively normally distributed, you have less need for HIGH and MEDIUM statistics. On sites with normally distributed data, I have seen no real benefit to "complex" USH/USM/USL, but on the site I'm currently annoying, I'm seeing a real benefit to the "book" recommended statistics. Does that help? _________________________________________________________________________ Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com. Share information about yourself, create your own public profile at http://profiles.msn.com.