i have 2-3 fileds in metricFieldSpecs. These columns captures taken to do some operation (e.g. time taken to sent -> delivery of a items). Any idea of how to get a histogram of this data (to be used in Superset)?

Afaik, there isn’t an inbuilt histogram function. You could use the percentileTDigest to get fast percentiles for histo. cc: @Jackie @Kartik Khare