Method and apparatus for hierarchical storage management for data base management systems

摘要

A hierarchical storage management system for database management systems that divides a database logically into separately managed regions, with each region being described by an entry in a vector kept in a regions file. The region entry contains a time stamp of the last time the region was accessed, the staging identifier of the region if it has been migrated, the base level backup staging identifier of the region if it has been baselined, and an indicator telling whether or not the region is resident online. Each managed region of the database is migrated to a separate staging file. When the database software issues a read or write input/output operation, the present invention sends the migration software a signal signifying this has occurred. The migration software of the present invention then updates the accessed time stamp, and checks to see if the region is resident. If it is not resident, it is staged in. The present invention creates and updates a migration candidate list ordered by date last accessed and region size. Both demand staging by the HSM, and user--initiated staging can then operate on the migration candidate list to migrate suitable files to tertiary storage.