Set an handler called when the connection receives notification on a channel.
<p/>
The handler is called with the {@link PgNotification} and has access to the channel name
and the notification payload.
@param handler the handler
@return the transaction instance
Set an handler called when the connection receives notification on a channel. <p/> The handler is called with the {@link PgNotification} and has access to the channel name and the notification payload.
@param handler the handler @return the transaction instance