Patent ID: 6535893
Filing Date: 2003-03-18
Classification: G06F,Y10S

Abstract:
A computer-implemented method for performing online reorganization of a database, comprising:(a) copying an original table space stored on the computer to a shadow table space; (b) identifying a starting and ending position for a log recording modifications made to original table space; (c) deriving an estimate of an elapsed time necessary for a last iteration against the shadow table space using the identified starting and ending positions; (d) when the derived estimate of the elapsed time necessary for a last iteration is greater than a specified maximum length of time that read-only access may be provided to the original table space, performing the log apply operations from the starting position to the ending position of the log against the shadow table space and repeating the method from step (b); and (e) when the derived estimate of the elapsed time necessary for a last iteration is less than or equal to the specified maximum length of time that read-only access may be provided to the original table space, draining all applications making modifications to the original table space; allowing read-only access to the original table space, performing the log apply operations from the starting position to the ending position of the log against the shadow table space, and then switching all of the applications from the original table space to the shadow table space.