Wikidata Extended Types
Wikidata Extended Types are functionally common datatypes which are not subtypes of any standard SQL scalar datatype. Because these datatypes are so frequently recurring, it is desirable that Wikidata support them directly by automatically handling their virtualized representation through a combination of standard SQL datatypes, as well as supporting the use of various logical and mathematical operators (>, =, etc.) on these extended types where the latters' semantics would be starightforward.
FUZZYDATE is an imprecise date expressed as a range of time. It is necessary when either there is not enough information to establish a precise date, or when the point in time inquestion is inherently imprecise. An example of the former is the birthdate of Homer, which scholars place sometime in the 8th Century BC- or (750BC, +/-50 years). An example of the latter is the beginning of the Jurassic period, the definition of which is not even conceptually well understood- thus (200 Million BC, +/-5 million years).