Patent ID: 7587429
Filing Date: 2009-09-08
Classification: G06F,Y10S

Abstract:
1. A method for making a consistent checkpoint of a computer database in a primary storage to a secondary storage, wherein the method comprises steps of: beginning a process of checkpointing by identifying at least one page in a database to be checkpointed, said at least one page being on the primary storage and comprising at least one data object, each said at least one data object being free of any indication of a pending status concerning the at least one data object being altered subsequent to said at least one page being identified to be checkpointed; after the beginning step, altering a first of said at least one data object by i) creating a new data object on said at least one page on said primary storage, ii) marking said new data object with a first pending status indicating that said new data object is an updatable copy of said at least one data object, and iii) marking said first data object with a second pending status indicating that said first data object will be replaced by said new data object with said first pending status after said first data object has been checkpointed, said new data object marked with said first pending status being accessible to transactions of said computer database on said primary storage; buffering, to a buffer on said primary storage, each of said at least one data object free of any indication of a pending status and said first data object marked with said second pending status to form a buffered contiguous page on said primary storage, said contiguous page being free of said new data object marked with said first pending status; writing said buffered contiguous page free of said new data object marked with said first pending status to the secondary storage; and after completing said writing step, replacing said first data object, having said second pending status and on said primary storage, with said new data object, and removing said first pending status from said new data object.