Semantic heterogeneity might sound like a meaningless bit of tech jargon, but it actually describes a subtle set of problems confronting many developers and DBAs. Anyone who's ever had to combine data sets from two different databases (and what DBA or database developer hasn't?) has probably encountered a semantic heterogeneity: data that doesn't match in format and therefore is difficult to merge. Combining databases when temperature is recorded in Celsius in one database and Fahrenheit in the ...