[Info-vax] The Future of Server Hardware?

[Paul Sture]

In article <nospam-208827.14195403102012 at news.chingola.ch>,
 Paul Sture <nospam at sture.ch> wrote:

> Sorts were screaming fast too.  In a traditional batch accounting system 
> for example, you could sort an input file into say customer account 
> number order and validate against the customer file, then sort again 
> into product number order and validate against the product file.  Repeat 
> and rinse for other fields which needed to be validated against a master 
> file.  Not only did this sorting mean you could work your way up each 
> master file's indexes in order, but by comparing each transaction with 
> the last, you only needed to validate against an index when the key 
> field changed.
>  

I'll clarify that a bit.  By sorting the input file into the key order 
of the master file you are validating against:

1. If the input file contains several thousand transactions for
   widget#123, you only need one lookup on the widgets file
   to validate all of them.

2. If your widgets master file index is on a dedicated disk, then
   the disk head will move up the index in order, and you may
   get the benefit of caching here as well.

It's a very different kettle of fish from multiple interactive users all 
needing validation concurrently.

-- 
Paul Sture