Is a value stored twice when using a tolowercase normalizer on keywords?

[DanglingNode]

Hi all,
I'm using a 'tolowercase' normalizer upon index (mapping) time to be able to find documents with value 'John Doe' when searching for 'john doe'.

Upon index creation:

       client.Indices.Create(
                    "some_index", 
                    c => c
                        .Settings(s => s
                            .Analysis(a => a
                                .Normalizers(n => n
                                    .Custom("lowercase", cn => cn.Filters("lowercase")))))

                        .Map<Person>(m => m.AutoMap())
                    );

The person object:

internal class Person {
    [Keyword(Normalizer = "lowercase")]
    public string Name {get; set;}
}

Does this mean more storage is used for the fields with this normalizer defined? So for documents having 'John Doe' as name. Will this value be stored as 'John Doe' and 'john doe'? Or does the normalization happen upon search computation time?

If the value is stored twice, are there other (better) solutions to avoid having to store more tokens?

[Mark_Harwood]

@DanglingNode

Does this mean more storage is used for the fields with this normalizer defined?

No, normalising typically reduces disk space because the search index doesn't contain all the case variations that might exist in different documents. Think of it like the word index at the back of a book - it would be bigger if it listed both page 10's Aardvark and page 33's aardvark as different entries