Rails: Full-Text Search related

Pg_Search & SearchKick are gems 

Pg_Search vs SearchKick
https://www.webascender.com/blog/rails-search-gems-searchkick-vs-pg_search/

Pg_Search

One of the best features of Postgres is the built-in, full-text search capabilities. The pg_search gem helps maximize these capabilities by providing a powerful, yet simple, search capability. pg_search is great for a basic search that will search multiple models, associations, and is able to hook into advanced Postgres features in the optional contrib package. This contrib package allows fuzzy and trigram searching.

ElasticSearch & SearchKick in Depth
https://www.webascender.com/blog/rails-elasticsearch-searchkick-depth/

SearchKick:
Github: https://github.com/ankane/searchkick
GoRails video: https://gorails.com/episodes/elasticsearch-with-searckick
DriftingRuby video: https://www.driftingruby.com/episodes/searchkick-and-elasticsearch

Other videos related to Search:
- Ruby on Rails - Railscasts #278 Search With Sunspot - https://www.youtube.com/watch?v=6ub9OYNvHZk
- Ruby on Rails - Railscasts PRO #343 Full-Text Search in PostgreSQL (pro) - https://www.youtube.com/watch?v=n41F29Qln5E
- RailsConf 2016 - Multi-table Full Text Search with Postgres By Caleb Thompson - https://www.youtube.com/watch?v=OzHhJPlgZaw