In Presto SQL how to create a map of array values and its count
If I have a table like below, how do I get the map of the count of unique values in the arrays in column2?IDColumn1Column2110[a, a, b, c]212[a, a, a]I would like something like the below:IDColumn1Column2110{a: 2, b: 1, c: 1}212{a: 3}I tried to use Presto's [histogram][1] for this. But it is an ...