Now that we have the index created, we can indexed a document into the index. The only requirement for a document to be indexed is that it should be a JSON document as Elasticsearch is schema-less and derives the storage schema based on the document structure indexed.

As shown in the following figure, the command to index a document is PUT {index-name}/{type}/{id}:

PUT datalake/contacts/101
{
  "id":101,
  "cell":"(478) 531-2026",
  "work":”1-906-774-1226",
  "email":"[email protected]"
}

Figure 24: Document Creation Query

As the document is indexed, Elasticsearch internally creates document mapping based on the data in the initial document. This mapping can be accessed as shown here:

GET datalake/_mapping/contacts

Figure 25: Retrieving Document Mapping via Query

A few observations from the preceding screenshot:

• Keyword analyzer is the default analyzer used for schema-less indexing
• Based on the input type, the type information in the schema has been derived
• Certain default validations have been put in place for text fields

These are very powerful features for a flexible indexing capability of a semi-structured or unstructured information.