> db.c.createIndex({a:1}) > db.c.insert({a:1}) WriteResult({ "nInserted" : 1 }) > db.c.aggregate({$group: {_id: "$a"}}) { "_id" : 1 } > db.c.explain().aggregate({$group: {_id: "$a"}}) // Distinct scan! > db.c.explain().aggregate([{$group: {_id: "$a"}}], {hint: {$natural: 1}}) // Still distinct scan
This is probably because of the special codepath here which doesn't consider the hint.
- related to
-
SERVER-41458 $natural hint overrides index filters
- Closed
-
SERVER-14227 add index hint support for distinct command
- Closed