Hi,

I've come across a lot of use cases where the business logic has demanded unique constraints on 1-2 fields that have been modeled as arrays on documents. The cases that only contain a single array field is already taken care of using unique indexes in MongoDB, however the cases with 2 array fields have required application level constraints since the database only supports a single array field in compound indexes. While multiple arrays in a single index would massively increase the size of the indexes, it would be very helpful if it would still be possible. If there are other limitations that makes it difficult to implement support for N number of array fields, then my request would be to increase the limit from 1 to 2, as this would solve all of the cases that I've encountered (and any reasonable cases that I could think of).

Thanks in advance,