January 2003
Intermediate to advanced
300 pages
15h 18m
English
Content preview from Data Quality
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20~
CHAPTER
9
Structure Analysis
captured. The inaccurate-fact data comes from primary key violations, denor-
malized key violations, derived column violations, or primary key/foreign
key violations.
Primary key violations include lack of uniqueness in the key itself. This
means that you have two or more rows in the data that have the same value for
the primary key. The inaccuracy is that all but one of the key values are
wrong. It may be that all of them are wrong.
If you are evaluating a natural key, the duplicate values should be investi-
gated carefully to be sure that it really is a natural key. In cases such
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I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.Addison B.
I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.Amir M.
I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.