On Fri, 13 Mar 2009, michael@stripped wrote:
> Explanation(5): The more you understand how the database is to be used,
> and the more complexity and thought you put into your database design, the
> less complex it will be to retrieve reliable information out of it.
> Furthermore, (and this is probably what makes me crazy when Nulls are
> evolved) after a ten year stretch of software development, where I and a
> team designed our own databases, I did a nine year stretch of statistical
> programming, using databases designed by other people, and Nulls in the
> data made the results unpredictable, and yeah, made me crazy! I had to
> write nightly processes to resolve inconsistencies in the data, if at
> least report inconsistencies. You know the old saying "Garbage in =
> Garbage out", to me Nulls are garbage, and if there is a good reason for
> nulls to be a part of good clean data then someone please help me
> understand that.
I'm in a argumentative mood today too. :-)
I have a database logging weather data. When a station does not report a
temperature, it is set to NULL. It would be a very bad idea to set it to 0
as this would ruin the whole statistics.
NULL is a perfectly valid information in many cases.