configure_connection

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 997
        def configure_connection
          if @config[:encoding]
            @raw_connection.set_client_encoding(@config[:encoding])
          end
          self.client_min_messages = @config[:min_messages] || "warning"
          self.schema_search_path = @config[:schema_search_path] || @config[:schema_order]

          unless ActiveRecord.db_warnings_action.nil?
            @raw_connection.set_notice_receiver do |result|
              message = result.error_field(PG::Result::PG_DIAG_MESSAGE_PRIMARY)
              code = result.error_field(PG::Result::PG_DIAG_SQLSTATE)
              level = result.error_field(PG::Result::PG_DIAG_SEVERITY)
              @notice_receiver_sql_warnings << SQLWarning.new(message, code, level, nil, @pool)
            end
          end

          # Use standard-conforming strings so we don't have to do the E'...' dance.
          set_standard_conforming_strings

          variables = @config.fetch(:variables, {}).stringify_keys

          # Set interval output format to ISO 8601 for ease of parsing by ActiveSupport::Duration.parse
          internal_execute("SET intervalstyle = iso_8601")

          # SET statements from :variables config hash
          # https://www.postgresql.org/docs/current/static/sql-set.html
          variables.map do |k, v|
            if v == ":default" || v == :default
              # Sets the value to the global or compile default
              internal_execute("SET SESSION #{k} TO DEFAULT")
            elsif !v.nil?
              internal_execute("SET SESSION #{k} TO #{quote(v)}")
            end
          end

          add_pg_encoders
          add_pg_decoders

          reload_type_map
        end