How to aggregate boolean values in elastic search?
First 0/1 representation is not exactly ES Boolean representation. There is a Boolean type for as true/false.Second stats aggregation can be only done on numeric field and not on string field. That is why it worked for 0/1 representation.
You can transform this value using scripts in extended stats
{ "aggs" : { ... "aggs" : { "grades_stats" : { "extended_stats" : { "field" : "grade", "script" : "_value == 'T' ? 1 : 0", } } } }}To see some example usage of scripting in aggregation , you can look here.