International Business Machines Corporation

David Tremaine

Adil Mohammad Sardar

Leo T M Lau

Philip Shawn Cox

Sean Douglas Perry

Miroslaw Adam Flasza

Leo Tat Man Lau

Robert T Berks

Aleksandrs Santars

Ivan Lew

Sam Sampson Lightstone

Matthew Albert Huras

Michael Jeffrey Winer

Gary Valentin

Catherine Suzanne McArthur

Mark Donald Leitch

Lee C Chu

Leo Lau

Michael T Ho

One or more processors determine whether a first procedure within a first program meets a first criterion. The first criterion is included in a plurality of criteria that are configured for pessimistic aliasing. Responsive to the determination, one or more processors determine whether to flag the first procedure for pessimistic aliasing.

Method for defining alias sets

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

Techniques are described for data redistribution. Embodiments store a first set of receiver location identifiers mapped to a document identifier and assigned to a first set of receiver locations storing relational data referencing the document identifier. Embodiments store a second set of receiver location identifiers mapped to the document identifier and assigned to a second set of receiver locations storing document data corresponding to the document identifier referenced by the relational data. Sender index keys are received separately from the relational data and the document data, the sender index keys referencing the document identifier and containing sender location identifiers. Embodiments determine, from the first set of receiver location identifiers and the second set of receiver location identifiers, which receiver location identifiers are mapped to the document identifier referenced by the sender index keys. The sender location identifiers are then replaced with the determined receiver location identifiers.

Redistribute native XML index key shipping

Techniques are described for data redistribution in a database system. Embodiments store a first set of receiver location identifiers mapped to a document identifier, the first set of receiver location identifiers assigned to a first set of receiver locations storing relational data referencing the document identifier. Embodiments further store a second set of receiver location identifiers mapped to the document identifier, the second set of receiver location identifiers assigned to a second set of receiver locations storing document data corresponding to the document identifier referenced by the relational data. Sender index keys are received separately from the relational data and the document data, the sender index keys referencing the document identifier and containing sender location identifiers. Embodiments determine, from the first set of receiver location identifiers and the second set of receiver location identifiers, which receiver location identifiers are mapped to the document identifier referenced by the sender index keys. The sender location identifiers are then replaced with the determined receiver location identifiers.

In one implementation, a method for sustaining database processing parallelism of one or more parallelized processes to build one or more index pages using pseudo record identifiers (PRIDs) is disclosed. The method comprises generating one or more PRIDs for one or more respective internal record formats (IRFs), inserting said generated PRIDs into a respective index key, generating a relational index of the PRID and a predetermined record identifier (RID) respectively determined in relation to said IRF, and building one or more index pages in relation to the relational index by comparing said RID and said PRID for their respective IRF in said relational index, and determining which one of said RID or said PRID to insert into said index page.

Method for maintaining parallelism in database processing using record identifier substitution assignment

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.

Apparatus and method for streamlining index updates in a shared-nothing architecture

The invention herein provides method and apparatus for managing attribute-tagged index entries contained in an index by assigning or tagging an index entry attribute indicator to a newly inserted index entry (that is, at the time when a key data value is inserted into the index, the key data value becomes a newly inserted index entry and an attribute indicator is tagged to the newly inserted index entry). The index entry can be placed anywhere within the index. Once a group of attribute-tagged index entries have been inserted into the index, the attribute identifiers can be switched off instantaneously (that is, the attribute associated with the attribute indicators is disabled).

Managing attributed-tagged index entries

A system and associated method load an input data stream into a multi-dimensional clustering (MDC) table or other structure containing data clustered along one or more dimensions, by assembling blocks of data in a partial block cache in which each partial block is associated with a distinct logical cell. A minimum threshold number of partial blocks may be maintained. Partial blocks may be spilled from the partial block cache to make room for new logical cells. Last partial pages of spilled partial blocks may be stored in a partial page cache to limit I/O if the cell associated with a spilled block is encountered later in the input data stream. Buffers may be reassigned from the partial block cache to the partial page cache if the latter is filled. Parallelism may be employed for efficiency during sorting of input data subsets and during storage of blocks to secondary storage.

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Markham, Canada

David Tremaine