[SERVER-480] figure out what to do with sorting by array sub-field - MongoDB Jira

XML

Word

Printable

JSON

the ensureIndex changes the output, which is bad.
not sure what should be correct, but having an index shouldn't change output.

db.foo.drop()
db.foo.save( { a : [

{ x : 2 }

] } )
db.foo.save( { a : [

{ x : 1 }

] } )
db.foo.save( { a : [

{ x : 3 }

] } )
db.foo.ensureIndex(

{ "a.x" : 1 }

)
db.foo.find().sort(

{ "a.x" : 1 }

).forEach( printjson );

related to

SERVER-8152 aggregation array sort differs from query/index array sort; causes aggregation results to change depending on sort optimizations

SERVER-429 btree change (Sorting and other) master case

SERVER-19402 Change semantics of sorting by array fields in find and aggregate

Participants:: Aaron Staple, auto, Eliot Horowitz, Remon van Vliet, Valentin