Re: Sounds like Wylie needs to go on an RDBMS course...
Well, the headline says "RDBMS", the opening sentence refers to "RDBMS", the previous paragraph refers to "a database engineer" and that same sentence states "how relational databases work" immediately before referencing PCA and and dimensionality reduction, so to me the article is pretty focussed on RDBMS.
I completely get that in the bigger picture, someone working with data analysis and value extraction should know about these things, but that's not what I would call a database engineer.
I definitely agree that the ICO audit team should know this stuff backwards, if they are going to be able to perform a meaningful inspection of any company's data handling.