Patents by Inventor Robert F. Bretl

Robert F. Bretl has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 6681226
    Abstract: Software and a method selectively apply a pessimistic concurrency control for each database update that conflicts with another database update. The method includes determining whether a database update conflicts with another database update, applying an optimistic concurrency control for each database update that does not conflict with another database update, and applying a pessimistic concurrency control for each database update that does conflict with another database update. This provides a selective locking concurrency control that selectively applies transaction serialization and locking only when transaction conflicts are detected. As a result, the selective locking concurrency control avoids livelock transaction failures and provides deterministic transaction completion without the computational expense of a conventional pessimistic concurrency control.
    Type: Grant
    Filed: January 30, 2001
    Date of Patent: January 20, 2004
    Assignee: Gemstone Systems, Inc.
    Inventors: Robert F. Bretl, Ramachandran Venkatesh
  • Publication number: 20020138483
    Abstract: Software and a method selectively apply a pessimistic concurrency control for each database update that conflicts with another database update. The method includes determining whether a database update conflicts with another database update, applying an optimistic concurrency control for each database update that does not conflict with another database update, and applying a pessimistic concurrency control for each database update that does conflict with another database update. This provides a selective locking concurrency control that selectively applies transaction serialization and locking only when transaction conflicts are detected. As a result, the selective locking concurrency control avoids livelock transaction failures and provides deterministic transaction completion without the computational expense of a conventional pessimistic concurrency control.
    Type: Application
    Filed: January 30, 2001
    Publication date: September 26, 2002
    Inventors: Robert F. Bretl, Ramachandran Venkatesh
  • Patent number: 6360219
    Abstract: A queue data structure is stored on a computer-readable medium to represent a queue or list. The data structure includes a head pointer that points to the last or most recent list element to have been removed from the queue, and a tail pointer that points to the most recently added list element in the queue. The head pointer and tail pointer may be implemented as separate objects. The queue data structure is applicable to computer arts such as transactional database management. The queue data structure can prevent concurrency conflicts that could otherwise occur when an object modified in one transaction (e.g. by one user) is modified by another concurrent transaction (e.g. by another user).
    Type: Grant
    Filed: December 16, 1998
    Date of Patent: March 19, 2002
    Assignee: Gemstone Systems, Inc.
    Inventors: Robert F. Bretl, Martin R. McClure
  • Patent number: 6256637
    Abstract: A virtual machine computer includes multiple threads and can support multiple simultaneous workspaces. Within each workspace, multiple threads are able to access objects simultaneously. Threads are orthogonal to workspaces so that threads are not locked to particular workspaces, workspaces are not locked to particular threads, and the sizes of the workspaces are configurable to the requirements of the transactions within the workspaces. Such a virtual machine may be utilized in a variety of applications including transactional database applications in which multiple users have access to information (e.g., objects) in one or more shared databases. Such applications typically require that data transactions involving the objects in the shared database be performed reliably so as to maintain the integrity of the objects, which are sometimes called persistent objects.
    Type: Grant
    Filed: May 5, 1998
    Date of Patent: July 3, 2001
    Assignee: Gemstone Systems, Inc.
    Inventors: Ramachandran Venkatesh, Allen J. Otis, Robert F. Bretl