How does custom serializer affect searching?

How does custom serializer affect searching?

I am trying to use NodaTime in my app. The app persists data in a mongodb
database. Consider the following class
public class SomeType
{
public ObjectId Id { get; set; }
public Instant Instant { get; set; }
[BsonDateTimeOptions(Kind = DateTimeKind.Local)]
public DateTime DateTime { get; set; }
[BsonDateTimeOptions(Kind = DateTimeKind.Utc)]
public DateTime DateTimeUtc { get; set; }
// public ZonedDateTime ZonedDateTime { get; set; }
// public LocalDateTime LocalDateTime { get; set; }
}
Without adding a custom serializer, the Instant property of the class
doesn't get stored in the db. Reading the document from the db also fails.
public class InstantBsonSerializer : BsonBaseSerializer
{
public override object Deserialize(BsonReader bsonReader, Type
nominalType, IBsonSerializationOptions options)
{
var ticks = bsonReader.ReadInt64();
return new Instant(ticks);
}
public override object Deserialize(BsonReader bsonReader, Type
nominalType, Type actualType, IBsonSerializationOptions options)
{
var ticks = bsonReader.ReadInt64();
return new Instant(ticks);
}
public override void Serialize(BsonWriter bsonWriter, Type
nominalType, object value, IBsonSerializationOptions options)
{
var instant = (Instant) value;
bsonWriter.WriteInt64(instant.Ticks);
}
}
I created the above serializer and registered it properly. I am now able
to save and retrieve instances of my class with the proper value set for
Instant.
My question is how does the C# driver handle searching using linq?
var list = mongoDatabase.GetCollection<SomeType>("SomeType")
.AsQueryable<SomeType>()
.Where(x => x.Instant <
Instant.FromDateTimeUtc(dateTime.ToUniversalTime()))
.ToList();
Console.WriteLine(list.Count);
I get the correct list of documents. I am trying to understand HOW mongodb
gets this data. Does it first load ALL data, deserialize it properly and
then filter? Or does it serialize the Instant value of the where clause
and use the serialized value to filter all documents, load matching ones
and then deserialize?
I tried seeing the query logged by the mongodb profiler, but its doesnt
seem to log anything. I have set the profiling level to 2.
In the case of Instant the serialized value is a long. But in case of
ZonedDateTime, the serialized value will be a document with two
properties. How will searching work in that case?