Abstract: The present invention reconstructs and illustrates incomplete change records by initially selecting an initial change record. The initial change record describes a change made to a target data object located at a target location in an electronic database. Next, a transaction log associated with the electronic database is searched for change records which modify the target data object. Eventually, a particular change record is located which contains a complete copy of the data object. Finally, the change records are applied to the complete copy of the data object, thereby bringing the complete copy of the target data object to a state as it existed before the change described by the initial change record was made to the target data object.

Abstract: The present invention reconstructs and illustrates incomplete change records by initially selecting an initial change record. The initial change record describes a change made to a target data object located at a target location in an electronic database. Next, a transaction log associated with the electronic database is searched for change records which modify the target data object. Eventually, a particular change record is located which contains a complete copy of the data object. Finally, the change records are applied to the complete copy of the data object, thereby bringing the complete copy of the target data object to a state as it existed before the change described by the initial change record was made to the target data object.

Abstract: The present invention reconstructs and illustrates incomplete change records by initially selecting an initial change record. The initial change record describes a change made to a target data object located at a target location in an electronic database. Next, a transaction log associated with the electronic database is searched for change records which modify the target data object. Eventually, a particular change record is located which contains a complete copy of the data object. Finally, the change records are applied to the complete copy of the data object, thereby bringing the complete copy of the target data object to a state as it existed before the change described by the initial change record was made to the target data object.

Abstract: A method for maintaining the performance of the system while identifying and reclaiming unreferenced tuples. A set of status bits is associated with each tuple, which are used to indicate the current state of the tuple, and whether it is in a transient state while the garbage collector, according to this invention, is examining it, thus permitting the garbage collector to run without locking out other processing. Further, the garbage collector uses the status bits to audit linked lists used by a database manager against linkage failure. Finally, the garbage collector compresses data and removes redundant data found while traversing the tuple structure of the database.

Abstract: A shared tuple method for storing data in a database which supports modification of view relations without causing anomalous changes to logically unrelated tuples in the same or other relations. A generated key is generated by the database which uniquely identifies data in a child tuple. As a result, virtual parent relations are referenced by an original primary key, but has its underlying attribute values stored in one or more secondary relations whose access is gained through stored generated keys. The application interface is unaffected, because the system transparently pieces together the virtual relation from the primary and one or more secondary relations.