rore/elasticsearch-cardinality-plugin

This plugin extends Elasticsearch providing a new type of aggregation and a REST action to estimate the cardinality (number of uniq terms) of a field.

Elasticsearch Cardinality Plugin

This plugin is outdated since elasticsearch 1.1.0 (http://www.elasticsearch.org/guide/en/elasticsearch/reference/current/search-aggregations-metrics-cardinality-aggregation.html).