This ticket aims to support a wider range of intervals which are not generated by type-bracketed and are still estimable by splitting the intervals into three as described in Multi-type Interval Estimation.

NOTE: A type-bracketed interval generated by find query {a: {$gt: 123}} is [123, "")

For examples

• [null, false]
• [123, true] 

A working implementation we could reuse is: https://github.com/10gen/mongo/pull/25547