MongoDb aggregate executing two times only to count my records-CodePudding

i've one question about find pageable and count my records in aggregate at same time, in my case i've this two aggregate:

This one is only to find records limited and pageables:

db.myCollection.aggregate([
             { $match : { ... }}, 
             { $project : { .. }}, 
             { $group : {... }},
             { $sort  : {... }},
             { $limit : 10}, { $skip : 10}])

And this other is only to count the amounts of records filtered and grouped whitout pageable:

db.myCollection.aggregate([
             { $match : { ... }}, 
             { $project : { .. }}, 
             { $group : {... }},
             { $count : "amount" }])

But i've a large database and this both aggregation is costly, so my question is: Could i get my records and count at the same time?

CodePudding user response：

I've reached results with facet, i've insert facets after the group:

{ $group : {... }},
{ $facet : {
  "data" : [{
      $project : { 
        _id : "$_id", 
        foo  : "$foo"
      }  
    }]}
},
{
  $project : {
      "amount" : { $size : "$data" },
      data : "$data"
  }},
{ 
  $unwind : {
       path: "$data"
 }},

{ $project : 
    {
        "amount" : 1,
        _id : "$data._id", 
         foo : "$data.foo"
     }
}

After this 4 operations i've the all datas with the amount of datas too.