autocomplete

controller.rb

class AutocompleteController < ApplicationController
  def index
    query = params[:query].downcase
    taxa = ::Taxon.where('lower("name") like ?', "#{query}%")
                  .limit(10)
                  
    render json: taxa
  end
end

migration.rb

class AddTaxaIndex < ActiveRecord::Migration[5.0]
  def change
    execute 'CREATE INDEX name_prefix ON taxa USING btree (lower ("name") text_pattern_ops);'
  end
end