count operation fetches all the objects.

[jyoon17]

https://github.com/ParsePlatform/Parse-SDK-Android/blob/master/Parse/src/main/java/com/parse/ParseRESTQueryCommand.java#L65-L71

https://github.com/ParsePlatform/Parse-SDK-Android/blob/master/Parse/src/main/java/com/parse/ParseQuery.java#L1318

While encoding parameters to generate a http request for count, setLimit(0) is ignored. As a result, it fetches every object (at most 100 objects).

[natario1]

@jyoon17 I’m not sure I get it, could you elaborate? count is supposed to count all objects.

[jyoon17]

@natario1 Yes, it is supposed to count all objects but it is NOT supposed to fetch all objects.

As you can see it here, countInBackground explicitly sets the limit parameter to zero in order to prevent from fetching all objects.

However, HTTP request encoder (https://github.com/ParsePlatform/Parse-SDK-Android/blob/master/Parse/src/main/java/com/parse/ParseRESTQueryCommand.java#L65-L71) ignores the limit parameter when it sees count parameter.

As a result, it will generate something like this:

GET /1/classes/GameScore?count=1

instead of

GET /1/classes/GameScore?limit=0&count=1

On the server side, a server will first find all the objects and then puts results under results since the limit parameter is undefined (https://github.com/parse-community/parse-server/blob/f7af48db895f58edcdbca383a5a5e1458bf88a31/src/RestQuery.js#L478-L482).

Then the server will also do counting and put the result under count.

The response would look like:

{
    "count": 11423,
    "results": [
          {"objectId": .... },
          {"objectId": .... },
          {"objectId": .... },
          {"objectId": .... },
          ...
    ]
}

I though fetching results is not desirable and please correct me if I am wrong.

[natario1]

I got it, thanks! I’ll look into this.

[natario1]

@jyoon17 thanks man, this was a nice catch, wonder how you noticed it.