Understanding the Elasticsearch query syntax:
https://logz.io/blog/elasticsearch-queries/
Tuning ElasticSearch for search speed:
https://www.elastic.co/guide/en/elasticsearch/reference/master/tune-for-search-speed.html
For example, search-optimized document modeling for Elasticsearch:
https://www.elastic.co/guide/en/elasticsearch/reference/master/tune-for-search-speed.html#_document_modeling
Tuning ElasticSearch for indexing speed:
https://www.elastic.co/guide/en/elasticsearch/reference/master/tune-for-indexing-speed.html
Shard sizing:
https://www.elastic.co/guide/en/elasticsearch/reference/master/size-your-shards.html