When deciding between a Tag Calculation Query and a Tag Historian Query, the main difference between the two is as follows:
Note that since Min/Max returns two values (the minimum and maximum value over the range), this calculation will generate two rows per Tag Path. This extra row will appear in the underlying data, even if the MinMax key isn't used in a table or chart, as it is part of the underlying data.
If we added Min/Max to our example above, the preview panel would look like the following:
Note that the other calculations (Average and Sum) are simply duplicated for both MinMax rows.