Patent ID: 6032160
Filing Date: 2000-02-29
Classification: G06F,Y10S

Abstract:
A space management system for use in managing storage allocation for the storage of data values of a data type corresponding to large data objects (LOBs) stored in storage locations of a data base of a computer system having a central processor, a memory unit, and a storage subsystem containing a LOB data space in which the LOB data values are stored, the space management system comprising:a plurality of regular-tier allocation page data structures that indicate, for a predetermined number of LOB data space storage locations comprising a regular-tier buddy space, whether the storage locations are free or allocated such that each regular-tier allocation page identifies free regular-tier buddy spaces of the LOB data space in which to store the LOB data value and thereby control data access to the regular-tier buddy spaces;a plurality of super-tier allocation page data structures of the LOB data space that indicate, for a predetermined number of regular-tier pages comprising a super-tier buddy space, whether the regular-tier pages are free or allocated, to identify one or more free super-tier buddy spaces in which to store the LOB data value, where the LOB data value has a size such that it cannot be stored in less than one super-tier buddy space, and thereby control data access to the super-tier buddy spaces, such that at least one super-tier allocation page identifies free super-tier buddy spaces over the entire LOB data space; anda data manager controller that manages the regular-tier and the super-tier allocation pages by receiving requests from users of the computer system for access to LOB data values and allocating storage locations in the LOB data space identified by the super-tier allocation pages and regular-tier allocation pages, respectively, as free for the storage of LOB data values and freeing selected LOB data space storage locations that are no longer needed for the storage of LOB data values.