sub document group by count

db.SLS_ORDER.aggregate( [
{
$group: {
_id: "$SalesPayment.ORACLE_ID",
count: { $sum: 1 }
}
},
{ $match: { count: { $gt: 1 } } }
]);

how to delete sub document in sub document on c#

{
  "_id": "binary_stuff",
  "Name": "MyApplication",
  "Settings": [
    {
      "_id": "binary_stuff",
      "Key": "ImportDirectory",
      "Value": "C:\data",
      "Overrides": [{
             "_id": "binary_stuff",
             "Name": "PathDirectory",
             "Value": "C:\anotherData"
       }]
    },
}

   var query = Query.And(Query.EQ("_id", applicationId),
                         Query.EQ("Settings.Key",  "ImportDirectory"));
        var update = Update.Pull("Settings.$.Overrides", new BsonDocument(){
            { "Name", "PathDirectory" }
        });
        database.Applications().Update(query, update);

Image resolution for mdpi, hdpi, xhdpi and xxhdpi

From a base image size, there is a 3:4:6:8:12:16 scaling ratio in drawable size by DPI.

LDPI - 0.75x
MDPI - Original size
HDPI - 1.5x
XHDPI - 2.0x
XXHDPI - 3x
XXXHDPI - 4.0x

For example, 100x100px image on a MDPI will be the same size of a 200x200px on a XHDPI screen.