Patent ID: 6792429
Filing Date: 2004-09-14
Classification: G06F,Y10S

Abstract:
A method of restructuring the physical storage of a table in a database, the table having a plurality of records and one or more partitions into which records of the table are grouped, each partition being stored in a file made up of a number of fixed-size blocks, the database further including control information describing the table, associated files and partitions, and including an audit trail describing updates, if any, to the records of the table, the method comprising:altering the control information to indicate that each partition of the table has a first format in which each partition is currently stored in a first storage unit; updating the control information to indicate that each partition of the table is enabled to be stored in a second format; selecting a partition to be restructured; copying the blocks of a first file, stored in a first location of the first storage unit and containing the selected partition of the table, from the first storage location to a second file at a second storage location of the second storage unit, while allowing updates to the table, including updates to the selected partition in the first file; altering the blocks in the second file to have the second format; updating any records in the selected partition in the second file based on the audit trail, while allowing updates to the table including updates to the selected partition at the first storage location; locking the table to prevent updates to the table, after updating any records in the second file based on the audit trail; updating any records in the selected partition at the second storage location based on the audit trail, while the table is locked; and unlocking the table to allow updates to the table including updates to the selected partition at the second storage location.