Max and Min function on mvfield(s)

[tombonfert]

• Min(X,...) and Max(X,...) functions take an arbitrary number of arguments and return the minimum and maximum per row, respectively.
• Currently, our implementation is good for single value fields in the input. We are calling Spark's 'least' and 'greatest' method.
• Our implementation fails or produces wrong results for the following inputs:
  • The only input argument is a mvfield -> Need to call 'array_min' or 'array_max' instead of 'least' or 'greatest'.
  • There are several mvfields as input -> Create array of input arrays -> Flatten -> call array_min / array_max
  • In Splunk it is also possible to provide a mixture of mvfields and svfields in the input.
• Solution: We need to know the data types of the input arguments.