A data type identifies what kind of value a field contains and guides how visualization tools and people treat it. A date dimension, for example, is not handled like a fruit-type dimension. section 3.2 section 3.3
Common fundamental data types include:
- Strings, numbers, dates, and Booleans; Booleans contain only true or false and support logical if statements. section 3.3 section 3.3.4
- Null represents nothing at all, while arrays and objects combine multiple basic values into more complex structures. section 3.6
Keep every value within a dimension or measure on the same data type. One stray string in a field of numbers can make the entire field behave as strings, producing errors or breaking the visualization. section 3.3.4
The stray string
Imagine a dimension containing a million numeric values and one accidental string. The visualization tool may treat every value as a string, so a tiny data-quality problem can become a very large chart problem. section 3.3.4
