Tuesday, July 10, 2007

Bill Inmon

Congratulations to our good friend Bill Inmon for his inclusion on this Computer World article. Bill is in good company listed alongside of Edgar (Ted) Codd, IBM fellow and Father of the relational database, John J. Cullinane, Founder, Cullinet Software Inc. Creator of the packaged software market. And other IT luminaries. Check out the article for the entire list. Here is the write up on Bill. Who: Bill Inmon What/where: CEO, Inmon Data Systems Inc. Why: Coined the term “data warehouse” in 1990 and is considered the father of the $28 billion industry. Inmon defined a data warehouse as a place where information is subject-specific, integrated, time-dependent and nonvolatile -- that is, more data can be added, but old data never changes. Advocates contend that businesses should have one data warehouse that creates data mart offspring. A prolific writer, Inmon has published more than 650 articles and 46 books -- so far

posted by Cobb @ 7:43 AM

Amdahl's Law

Amdahl's law, named after computer architect Gene Amdahl, is used to find the maximum expected improvement to an overall system when only part of the system is improved. It is often used in parallel computing to predict the theoretical maximum speedup using multiple processors.

The generalized Amdahl's law is:

\frac{1}{\sum_{k=0}^{n}{\big(\frac{P_k}{S_k}\big)}}

where

  • P_k \ is a percentage of the instructions that can be improved (or slowed),
  • S_k \ is the speed-up multiplier (where 1 is no speed-up and no slowing),
  • k \ represents a label for each different percentage and speed-up, and
  • n \ is the number of different speed-up/slow-downs resulting from the system change.

posted by Cobb @ 7:41 AM