How Many Copies Does It Take to Screw Up the Data?

15 September 2008

There is an adage in information theory – keep data in one place – aimed at reducing the effort required to keep multiple copies up-to-date.  In practise, it isn’t followed much.  The general perception is that copying is easy.  The effect is the same as saying “quality costs too much”.

Extra copies are out of date, costly to maintain, make extra work, and often lead to corrupt data.

My advice: learn to use the tools to ensure the data stays in one place.  You’ll get more accurate results with less work.

SQL queries are easy once you learn how and quality does save money.