MongoDB allowDiskUse not working..

Question

Experts.

I\'m new to MongoDB, but know enough to get my self in trouble.. case in point:

db.test.aggregate(
[
    {$group: {_id: {email: \"$email\", ge         


        

Answer 1

Please use aggregate query in run command,it will allow to use allowDiskUse tag.

db.runCommand(
   { aggregate: "test",
     pipeline: [
                {$group: {_id: {email: "$email", gender: "$gender"}, cnt: {$sum: 1}}}, 
                {$group: {_id: "$_id.email", cnt: {$sum: 1}}}, 
                {$match: {cnt: 2}}
               ],
     allowDiskUse: true
   }
)