method for finding matching geo campaigns

gistfile1.rb

def self.find_matching_campaigns_by_geo(contact)
    matching_campaigns = []
    Campaign.all.each do |campaign| 
      campaign.geos.each do |geo|
        match = Geo.where(id: contact.geo.id).includes(:geo_polygons).joins("LEFT JOIN geo_polygons as container ON container.geo_id = #{geo.id}").where('ST_Within(geo_polygons.poly, container.poly)')
        matching_campaigns << campaign unless match.empty?
      end
    end
    matching_campaigns
end

Not sure though... but I think you'll need to use Campaign.all.find_each instead of Campaign.all.each to make the query memory efficient. See this => http://api.rubyonrails.org/classes/ActiveRecord/Batches.html#method-i-find_each