Sort NULL Values
A NULL value is defined as the smallest value for its corresponding data type. Therefore, when sorting in an ascending order, NULL values always rank first.
x = 1 2 NULL NULL 3;
x;
// output
[1,2,,,3]
sort!(x);
// output
[,,1,2,3]
// sort x in an ascending order with NULL values on the top
sort!(x,false);
// output
[3,2,1,,]
// sort x in a descending order with NULL values on the bottom
A negative infinity (-inf) value imported from external source or generated by calculations is smaller than NULL.
// use the float function to create a negative inf and compare it with NULL
-float("inf")<NULL
// output
true