Autocomplete suggestions for available bucket keys of terms aggregation in elasticsearch

Question

At UI I need to show the autocomplete suggestions which gives me the terms containing the searched term. e.g. if I search per I may get suggestions as Peru, Perry, Casper, Naperville, Cooperstown etc. The search box is to search/filter on a filed which is being used/shown as the terms aggregation for cities. This field type is array, so one document can have multiple cities. The auto-suggestions should only have the cities from available/resulted documents.

I am aware to use the filter Feature of terms aggregation with the proper regex. https://www.elastic.co/guide/en/elasticsearch/reference/current/search-aggregations-bucket-terms-aggregation.html#_filtering_values_4

But I am looking for a better solution available in elasticsearch which can provide me the fastest results.

Answer 1

Your best option would be to use wildcard field new keyword data type introduced by Elasticsearch. For more information check official documentation of Elastic about wildcard field here. This keyword field type is optimized for wildcard query.