Object and nested types #

object #

JSON documents are hierarchical in nature: the document may contain inner objects which, in turn, may contain inner objects themselves. The object type introduces inner objects.

{
  "album": {
    "artists": ["Bill Danoff", "Taffy Nivert", "John Denver"]
  }
}

In the above JSON document, field “album” is of type object.

Parameters for object fields #

• realtime — an object field’s realtime parameter would overwrite its sub-fields’ realtime parameter, even when they are explicitly set.
• index — an object field’s index parameter would overwrite its sub-fields’ index parameter, even when they are explicitly set.
• properties
• profile
• source / column / store

Support indexing multiple values #

Yes

nested #

An object with nested set to true — also accepted directly as "type": "nested" (ES form; identical schema). Sub-fields are indexed with ordinal tagging so that query clauses evaluate per inner object instead of across objects — the basis of the nested query.

PUT /my-collection/_schema
{
  "diff": {
    "reviews": {
      "type": "nested",
      "properties": {
        "author": {"type": "keyword"},
        "stars": {"type": "integer"}
      }
    }
  }
}

The alias implies nested: true; opt out explicitly with {"type": "nested", "nested": false} for a plain object. properties may be empty — the dynamic schema fills them. Readback (GET /<target>/_schema) presents stored object+nested pairs back as "type": "nested", so the schema round-trips.

Negative example — nested on a non-object field is rejected with 400 mapper_parsing_exception (unknown parameter [nested]):

PUT /my-collection/_schema
{ "diff": { "title": { "type": "text", "nested": true } } }   # 400

Parameters for nested fields #

• nested (true)
• properties
• realtime
• index
• profile
• source / column / store

Support indexing multiple values #

Yes — an array of inner objects.