Introducing indexes

As we discussed before, DocumentDB is a schema-free database containing JSON documents. By default, DocumentDB applies indexing to all document properties. This means you can specifically query for all the properties inside a document.

Explaining default indexing

Internally, DocumentDB represents all documents as trees. A dummy root node is created to make every document accessible via this root node. Every property of a document is a node in the tree representation.

The following code illustrates how one of our PersonInformation class's document is represented as a tree in JSON:

{
  "LastName": "Doe",
  "FirstName": "John",
  "DateOfBirth": {
    "Date": "1971-01-01T00:00:00",
    "Epoch": 31536000
  },
  "NumberOfHomeAutomationDevices": 1,
  "HomeAutomationDevices": [
    {
      "Manufacturer": "Contoso Inc.",
      "Type": "Heater...