1. A method of processing a database comprising information regarding hardware design language (“HDL”) events occurring during a simulation of a hardware design, the method comprising: identifying in the database all HDL events comprising observability events; obtaining from each of the identified observability HDL events information pertaining to a signal driving the identified observability HDL event observed on an observability bus; and creating a data structure comprising a plurality of entries, wherein each of the entries corresponds to one of the signals observed on the observability bus and contains signal information pertaining to the one of the observed signals.