Patents Represented by Law Firm Baker, Maxcham, Jester & Meador
  • Patent number: 5333303
    Abstract: Enhanced data availability occurs in a write-ahead logging, transaction-oriented database system by permitting new transactions to acquire access to data while restart recovery operations are proceeding. The invention permits new transactions to acquire access to data during restart recovery UNDO processing on the condition that the last update to the data occurred before a commit point measured by the beginning of the earliest-commencing transaction with uncommitted updates which was still executing when a system failure initiated restart recovery operations. During REDO processing, a transaction is permitted access to data which, in addition to meeting the commit point condition, is not in a data structure subject to the REDO processing.
    Type: Grant
    Filed: March 28, 1991
    Date of Patent: July 26, 1994
    Assignee: International Business Machines Corporation
    Inventor: Chandrasekaran Mohan