Indexing data that is not flat

Not all data is flat like the data we have been using so far in this book. Of course, if we are building the system that Elasticsearch will be a part of, we can create a structure that is convenient for Elasticsearch. Of course, the structure can't always be flat, because not all use cases allow that. Let's see how to create mappings that use fully-structured JSON objects.

Data

Let's assume that we have the following data (we will store it in the file named structured_data.json):

{
  "book" : {
    "author" : {
      "name" : {
        "firstName" : "Fyodor",
        "lastName" : "Dostoevsky"
      }
    },
    "isbn" : "123456789",
    "englishTitle" : "Crime and Punishment",
    "year" : 1886,
    "characters" : [
      {
        "name" : "Raskolnikov"
      }, 
      {
        "name" : "Sofia"
      }
    ],
    "copies" : 0
  }
}

As you can see in the preceding code, the data is not flat; it contains arrays and nested objects. If we would like to create mappings...