Mapping arrays
An array or multivalue fields are very common in data models (such as multiple phone numbers, addresses, names, alias, and so on), but not natively supported in traditional SQL solutions.
In SQL, multivalue fields require the creation of accessory tables that must be joined to gather all the values, leading to poor performance when the cardinality of records is huge.
Elasticsearch, which works natively in JSON, provides support for multivalue fields transparently.
Getting ready
You need an up-and-running Elasticsearch installation as we described in the Downloading and installing Elasticsearch recipe in Chapter 2, Downloading and Setup.
To execute curl via the command line, you need to install curl for your operative system.
How to do it...
Every field is automatically managed as an array. For example, to store tags for a document, the mapping will be:
{
"document" : {
"properties" : {
"name" : {"type" : "keyword"},
"tag" : {"type" : "keyword...
