Orderasc/desc by object that is missing the field data

hi @MichelDiz

i have this finding:
with this same query, i queries this multiple times on ratel ui,
and 50% of the time, it return results with actual data, but another 50% only return records with uid field (other records without created_at). and i could not delete those uid only records

query all($nothing: string){
	users(func: eq(_type, "users"), first: 10, orderdesc: created_at)   {
		uid
		email
		username
		password
		first_name
		last_name
		mobile_no
		office_no
		gender
		country
		confirmed_at
		locked_at
		deleted_at
		reset_token
		status
		signup_type
		online
		online_at
		ip_address
		created_at
		updated_at
		roles : with_role {
			uid
			name 
		}
		work_for : work_for {
			uid
			code
			name
			status
			country
			created_at
			updated_at 
			 
		}
	}

	users_count(func: eq(_type, "users"))  @filter(has(created_at)) {
		count(uid)
	}
}

ok result:

{
  "data": {
    "users": [
      {
        "uid": "0xea63",
        "email": "dsfsdf@example.com",
        "username": "dsfsdf@example.com",
        "password": "",
        "first_name": "dsfsd",
        "last_name": "dsfdsf",
        "mobile_no": "4",
        "office_no": "",
        "gender": "M",
        "country": "AD",
        "confirmed_at": "0001-01-01T00:00:00+06:55",
        "locked_at": "0001-01-01T00:00:00+06:55",
        "deleted_at": "0001-01-01T00:00:00+06:55",
        "reset_token": "",
        "status": 1,
        "signup_type": "email",
        "online": 0,
        "online_at": "0001-01-01T00:00:00+06:55",
        "ip_address": "",
        "created_at": "2018-10-16T09:24:48.24963+08:00",
        "updated_at": "2018-10-16T09:25:31.91972Z"
      },
      {
        "uid": "0xea62",
        "email": "ddsfsdf@example.com",
        "username": "ddsfsdf@example.com",
        "password": "",
        "first_name": "sdfdss",
        "last_name": "dfdsd",
        "mobile_no": "2324324",
        "office_no": "",
        "gender": "M",
        "country": "",
        "confirmed_at": "0001-01-01T00:00:00+06:55",
        "locked_at": "0001-01-01T00:00:00+06:55",
        "deleted_at": "0001-01-01T00:00:00+06:55",
        "reset_token": "",
        "status": 1,
        "signup_type": "email",
        "online": 0,
        "online_at": "0001-01-01T00:00:00+06:55",
        "ip_address": "",
        "created_at": "2018-10-15T03:00:36.077012+08:00",
        "updated_at": "2018-10-16T07:26:56.430786Z",
        "roles": [
          {
            "uid": "0xc369",
            "name": "superadmin"
          },
          {
            "uid": "0xc36b",
            "name": "manager"
          },
          {
            "uid": "0xc36c",
            "name": "staff"
          }
        ]
      },
      {
        "uid": "0x2720",
        "email": "test5@test.com",
        "username": "test5@test.com",
        "password": "",
        "first_name": "sdfsdf tan",
        "last_name": "sdfdsf sdfdsf",
        "mobile_no": "2423432",
        "office_no": "",
        "gender": "M",
        "country": "MY",
        "confirmed_at": "0001-01-01T00:00:00+06:55",
        "locked_at": "0001-01-01T00:00:00+06:55",
        "deleted_at": "0001-01-01T00:00:00+06:55",
        "reset_token": "",
        "status": 0,
        "signup_type": "email",
        "online": 0,
        "online_at": "0001-01-01T00:00:00+06:55",
        "ip_address": "",
        "created_at": "2018-09-14T09:03:48.808329+08:00",
        "updated_at": "2018-10-16T05:56:07.528755Z",
        "roles": [
          {
            "uid": "0xc36b",
            "name": "manager"
          }
        ]
      },
      {
        "uid": "0x271e",
        "email": "tester@tester.com",
        "username": "tester@tester.com",
        "password": "",
        "first_name": "sdfsdfsdfdsf",
        "last_name": "sdfdsfdsf",
        "mobile_no": "3432423432",
        "office_no": "",
        "gender": "F",
        "country": "MY",
        "confirmed_at": "0001-01-01T00:00:00+06:55",
        "locked_at": "0001-01-01T00:00:00+06:55",
        "deleted_at": "0001-01-01T00:00:00+06:55",
        "reset_token": "",
        "status": 0,
        "signup_type": "email",
        "online": 0,
        "online_at": "0001-01-01T00:00:00+06:55",
        "ip_address": "",
        "created_at": "0001-01-01T00:00:00+06:55",
        "updated_at": "2018-10-16T09:25:17.077452Z",
        "roles": [
          {
            "uid": "0xc36a",
            "name": "admin"
          }
        ]
      },
      {
        "uid": "0x271f",
        "email": "test@test.com",
        "username": "test@test.com",
        "password": "",
        "first_name": "cdscdscds",
        "last_name": "tan",
        "mobile_no": "4324324324324234534",
        "office_no": "",
        "gender": "M",
        "country": "MY",
        "confirmed_at": "0001-01-01T00:00:00+06:55",
        "locked_at": "0001-01-01T00:00:00+06:55",
        "deleted_at": "0001-01-01T00:00:00+06:55",
        "reset_token": "",
        "status": 0,
        "signup_type": "email",
        "online": 0,
        "online_at": "0001-01-01T00:00:00+06:55",
        "ip_address": "",
        "created_at": "0001-01-01T00:00:00+06:55",
        "updated_at": "2018-10-16T09:23:08.259463Z"
      }
    ],
    "users_count": [
      {
        "count": 5
      }
    ]
  },
  "extensions": {
    "server_latency": {
      "parsing_ns": 75100,
      "processing_ns": 12097800,
      "encoding_ns": 1925700
    },
    "txn": {
      "start_ts": 90490,
      "lin_read": {
        "ids": {
          "1": 4989
        }
      }
    }
  }
}

uid only result:

{
  "data": {
    "users": [
      {
        "uid": "0x2716"
      },
      {
        "uid": "0x2715"
      },
      {
        "uid": "0x2713"
      },
      {
        "uid": "0x2712"
      },
      {
        "uid": "0x271d"
      },
      {
        "uid": "0x2717"
      },
      {
        "uid": "0x271c"
      },
      {
        "uid": "0x271b"
      },
      {
        "uid": "0x2711"
      },
      {
        "uid": "0x2719"
      }
    ],
    "users_count": [
      {
        "count": 5
      }
    ]
  },
  "extensions": {
    "server_latency": {
      "parsing_ns": 303600,
      "processing_ns": 13727200,
      "encoding_ns": 1918800
    },
    "txn": {
      "start_ts": 90489,
      "lin_read": {
        "ids": {
          "1": 4988
        }
      }
    }
  }
}