Can't use UUID in variable expansion on PostgreSQL hstore

[devinfoley]

trafficstars

@items = @items.where("id > ?", UUIDTools::UUID::parse_hexdigest(params[:since_id])) if params[:since_id]

[ivanoblomov]

Rails 4 now has native UUID support for Postgres. See http://labria.github.io/2013/04/27/rails-4-uuid-primary-keys-with-postgresql/.