connect

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 936
        def connect
          @connection = PGconn.connect(*@connection_parameters)
          PGconn.translate_results = false if PGconn.respond_to?(:translate_results=)

          # Ignore async_exec and async_query when using postgres-pr.
          @async = @config[:allow_concurrency] && @connection.respond_to?(:async_exec)

          # Use escape string syntax if available. We cannot do this lazily when encountering
          # the first string, because that could then break any transactions in progress.
          # See: http://www.postgresql.org/docs/current/static/runtime-config-compatible.html
          # If PostgreSQL doesn't know the standard_conforming_strings parameter then it doesn't
          # support escape string syntax. Don't override the inherited quoted_string_prefix.
          if supports_standard_conforming_strings?
            self.class.instance_eval do
              define_method(:quoted_string_prefix) { 'E' }
            end
          end

          # Money type has a fixed precision of 10 in PostgreSQL 8.2 and below, and as of
          # PostgreSQL 8.3 it has a fixed precision of 19. PostgreSQLColumn.extract_precision
          # should know about this but can't detect it there, so deal with it here.
          money_precision = (postgresql_version >= 80300) ? 19 : 10
          PostgreSQLColumn.module_eval("def extract_precision(sql_type)\nif sql_type =~ /^money$/\n\#{money_precision}\nelse\nsuper\nend\nend\n")

          configure_connection
        end