Реализация Bulk Insert для PostgreSQL в Rails 5

application_record.rb

class ApplicationRecord < ActiveRecord::Base
  self.abstract_class = true

  def self.bulk_insert(data)
    # @type [PG::Connection] conn
    conn = self.connection.raw_connection
    raise NotImplementedError.new 'Database Driver not supported!' unless conn.class.to_s == 'PG::Connection'

    raise ArgumentError "Data not an Array of Hashes!" unless data.is_a?(Array) && data.all? {|rec| rec.is_a? Hash }
    return nil unless data.count > 0
    fields = data[0].keys
    values = data.map { |item| item.values }

    # Создаём Prepared Statement
    prepared_name = 'bulk_insert'
    begin
      conn.exec("DEALLOCATE #{prepared_name}")
    rescue PG::InvalidSqlStatementName
      # Ignored
    end
    raw_fields = fields.map { |key| conn.escape_string(key)}.join(', ')
    raw_values = fields.each_with_index.map { |x,index| "$#{index+1}" }.join(', ')
    conn.prepare(prepared_name, "INSERT INTO #{self.table_name} (#{raw_fields}) VALUES(#{raw_values})")

    # Запускаем в транзации insert для каждой записи
    conn.exec("START TRANSACTION")
    values.each { |record| conn.exec_prepared(prepared_name, record) }
    conn.exec("COMMIT")
  end

end