International Business Machines Corporation

Philip Shawn Cox

David Tremaine

Adil Mohammad Sardar

Leo T M Lau

Leo Tat Man Lau

Leo Lau

A method and system for facilitating an undo operation. In one embodiment, the method includes generating a plurality of control files, where each of the control files is associated with a batch of data that is received from a sending partition during a redistribution process, and where each control file includes a list of pages and corresponding ranges of rows of data that have been appended to the pages. The method also includes writing the control files to a persistent memory for each control file where all of the associated rows of the respective consistency point have been appended to pages and written to a persistent memory. The method also includes, in response to an interruption in the redistribution process, identifying pages and rows to be deleted during an undo operation based on the plurality of control files.

Efficient undo-processing during data redistribution

A method and system for optimizing data redistribution in a database. In one embodiment, the method includes moving, during a first scan, outgoing records from a sending partition to one or more receiving partitions, where free space is created in the sending partition due to the outgoing records leaving the sending partition. The method also includes filling, during the first scan, some of the free space with remaining records that do not leave the sending partition.

Dynamic data compaction for data redistribution

The invention relates to a method and apparatus of distributing data in portioned databases operating on a shared-nothing architecture. The invention provides two independent streams of data, where a first stream sends table data, and the second stream sends LOB data, to a receiving partition. The receiving partition re-couples the LOB data with the table data. Using two independent streams to distribute LOB data can increase data redistribution since large amounts of input/output is not performed to handle the sending of LOB data in a coupled fashion.

Method and apparatus of distributing data in partioned databases operating on a shared-nothing architecture

An apparatus and method to streamline updates to an index in a shared-nothing architecture. The apparatus may include an association module, a consolidation module, and a processing module. The association module may associate index update requests with an index. The index update requests may be configured to update the index in response to a redistribution of data in a data table. The consolidation module may compile the index update requests prior to processing and consolidate the index update requests into a smaller number of simplified index update requests to achieve substantially the same result. The processing module may then independently process the simplified index update requests and update the index accordingly.

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Thornhill, Canada

Philip Shawn Cox