Find duplicates amongst mongodb collections

Question

Objective is to find field values which exists in more than one collection in a single mongodb database. Assume, each collection has similar document model on basis of type or number of fields within. Note . There is a unique id field in every collection whose value may or may not differ in fellow collections. Aim is to deduce all those collections which have these unique id values in common.

One solution is that if I follow brute force technique.

Solution.. traverse entire collection one by one and match every unique id values with each of those in other collections...

Are there any better solutions available?

Answer 1

There is no solution to this in MongoDB. Things are supposed to be embedded and there's usually no real correlation between collections. Even $lookup was introduced with some reluctance . I believe your solution is already the best there is.