Histogram aggregations: support decimal intervals

[jpountz]

Fork of #3810 and #3799. Decimal intervals would be useful for certain data types such as currencies, temperatures, lengths ...

[hudsonb]

+1

[jakegibson]

+1

[marcosg3]

+1
We came across this limitation on one of our projects, has there been any traction on this one?

[ignaciovazquez]

+1

[roblovelock]

+1
I am currently working around this issue by running a script (probably not the most efficient)

"aggs" : {
"decimalValueHistogram" : {
"terms": {
"field": "value",
"script" : "_value % interval < 0 ? _value -((_value % interval) + interval) : (_value - (_value % interval))",
"lang" : "expression" ,
"params": {
"interval" : 0.05
}
}
}
}

[ESamir]

+1

[sylvinus]

+1. Would be incredibly useful and avoid storing lots of duplicate columns, which is our only workaround for now :/