Re: Slow AS400 performance

[vhamberg@xxxxxxxxxxx]

Hi Jerry

I would think that random access by suitable key would still be fast. A table 
scan or, as you say, input primary or input full procedural arrival would be 
disastrous, with the luck of the draw based on where the record is located in 
the PF. But there are other areas where performance will be affected, such as 
disk space rising too high and index maintenance. The latter probably gets 
amortized and is not especially noticeable.

JMHO
Vern

-------------- Original message -------------- 
From: Jerry Adams <jerry@xxxxxxxxxxxxxxx> 

> Al, 
> 
> This intrigues me because it just so happens that I'm working on a 
> project to unarchive history. The current process is to back off the 
> sales history to a separate library at year end. 
> 
> 
> So far I've merged the last two year's with the current year's history 
> (in a test environment, of course). There are no discernible 
> differences to me (but I'm blind in one eye and can't see too well out 
> of the other one) as far as inquiry goes. The inquiries do ask the 
> requestor for the customer and, optionally, a starting date. 
> 
> 
> Naturally, if I was reading the sales history as an Input Primary, I 
> would expect things to take longer. Is this what you are talking about, 
> or is there some impact on the random searches (inquiries)? What kind 
> of activity other than the I/P would adversely impact a situation such 
> as this? 
> 
> 
> Thanks. 
> 
> * Jerry C. Adams 
> *IBM System i Programmer/Analyst 
> B&W Wholesale Distributors, Inc.* * 
> voice 
> 615.995.7024 
> fax 
> 615.995.1201 
> email 
> jerry@xxxxxxxxxxxxxxx 
> 
> 
> 
> Al Mac wrote: 
> 
> > Depending on your applications, archiving can dramatically improve 
> > performance. Let's suppose for example, people are using an inventory 
> > history inquiry program and the history has 10 years of data, but 99% of 
> > the people only need to see what is in the last 2 weeks. 
> > 
> > Having 500 weeks of data in the file can slow access for people who only 
> > need to see 2 weeks worth. Archiving solution makes the data available to 
> > the 1% applications that need to see 500 weeks, while performance 
> > dramatically improved for the 99% of your users. 
> > 
> > There's bunch of people on these lists who are familiar with the various 
> > archiving alternatives and can elucidate further if this interests you. 
> > 
> > - 
> > Al Macintyre 
> > http://en.wikipedia.org/wiki/User:AlMac 
> > BPCS/400 Computer Janitor ... see 
> > http://radio.weblogs.com/0107846/stories/2002/11/08/bpcsDocSources.html 
> > 
> > 
> 
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