International Business Machines Corporation

Bruce Gilbert Lindsay

Elizabeth Belva Hamel

Serge Bourbonnais

Eugene Jon Shekita

Roger C Raphael

Mir Hamid Pirahesh

Stephen James Todd

Paul Sherwood Taylor

Sridhar Rajagopalan

Melvin R Zimowski

Roger A Reinsch

Nicolas G Adiba

Rakesh Agrawal

Guy Maring Lohman

Matthew Albert Huras

Michael Jeffrey Winer

David C Sharpe

Brian Thinh-Vinh Tran

Nelson Mendonca Mattos

Robert Peter Resch

Robert J Grafe

Patricia G Selinger

Linda Gail DeMichiel

John G Adair

Ning Li

Yun Yu Wang

Vijayshankar Raman

Ronald Jason Barber

Calisto Paul Zuzarte

Kevin Scott Beyer

Inderpal Singh Narang

David Everett Simmen

Roberta Jo Cochrane

Somil Kulkarni

Nattavut Sutyanyong

Catherine Suzanne McArthur

Harish Deshmukh

Daniel Costante Zilio

Robert Neugebauer

Jaime F Anaya

Leslie Anne Cranston

Linqi Liu

Daniel J Coyle, Jr

Nelson Hop Hing

Richard A Demers

Gene Y Fuh

Siqun Li

Linda Gail De Michiel

Gurmeet Singh Manku

Roger Alan Reinsch

Adam J Storm

Bishwaranjan Bhattacharjee

Sam Sampson Lightstone

Sriram Kolinjivadi Padmanabhan

Ian R Finlay

Saileshwar Krishnamurthy

Christian Marcelo Garcia-Arellano

Timothy Ray Malkemus

Kathryn Heninger Britton

Honesty Cheng Young

Tuong Chanh Truong

Jun Rao

Jyh-Herng Chow

John Frederick Hornibrook

Yat On Lau

Clarence Madison Pruet, Iii

Steven K Elliot

Monica Sachiye Urata

William T O'Connell

Gene Y C Fuh

Amit Radheshyam Somani

Laura Myers Haas

Jeffrey James Goss

Miroslaw Adam Flasza

Andrew P Citron

Dieu Quang La

Michelle Mei-Chiou Jou

Kaarel Truuvert

Rajendra Bhagwatisingh Panwar

Matthew James Carroll

Petrus Kai Chung Chan

Adriana Zubiri

Richard R Sanders

Kenneth Salem

Geoffrey Peddle

Surendra Kumar Verma

Sirdhar Rajogopalan

Siquan Li

Robert D Jackson

Guido Rost

Dusan Ecimovic

Budi Surjanto

Chengfei Liu

Michael E Murphy

Robert L Sunday

Jens Stankiewitz

Dan J Coyle, Jr

Serge Philippe Rielau

Daniel Jerome Coyle

John Gary Adair

A method and system for distributing tasks from an external application among concurrent database application server instances in a database system for optimum load balancing, based on consensus among the instances. Each application instance identifies a task partition ownership by those in a membership group based on a time window and generates a new membership group and partition ownership based on the current partition ownership. The instance makes the new membership group and partition ownership known to other members by recoding them in the membership table and partition map. Each participation by an instance in the membership group is identified by a random number. The new membership group and partition ownership are generated and adjusted based on an average partition allocation to achieve consensus among the instances.

Method and system for distributed task dispatch in a multi-application environment based on consensus

A mechanism is provided for handling transaction messages in asynchronous data replication in a database system, in which the database system includes a source node and a target node, and each transaction message has information concerning a row change to a table copy at the source node. The mechanism determines whether a first transaction message has a dependency on a preceding non-completed transaction message. Responsive to the first transaction message having a dependency on the preceding non-completed transaction, the mechanism holds the first transaction message, completes the preceding non-completed transaction message including applying the row change associated with the preceding non-completed transaction message to the table copy at the target node, and responsive to completing the preceding non-completed transaction message, and releases the first transaction message and applying the row change associated with the first transaction message to the table copy at the target node.

Replicating data across multiple copies of a table in a database system

A mechanism for handling transaction messages in asynchronous data replication in a database system, in which the database system includes a source node and a target node, and each transaction message has information concerning a row change to a table copy at the source node. The mechanism determines whether a first transaction message has a dependency on a preceding non-completed transaction message. Responsive to the first transaction message having a dependency on the preceding non-completed transaction, the mechanism holds the first transaction message, completes the preceding non-completed transaction message including applying the row change associated with the preceding non-completed transaction message to the table copy at the target node, and responsive to completing the preceding non-completed transaction message, releases the first transaction message and applying the row change associated with the first transaction message to the table copy at the target node.

Methods and systems are provided for executing a simulation of an operation in a data processing system. In one implementation, the method includes executing an operation under a first set of conditions, determining a characteristic associated with the execution of the operation under the first set of conditions, and executing a simulation of the operation under a second set of conditions different from the first set of conditions. The simulation of the operation is constrained by the determined characteristic. The method can further include determining a cost/benefit of executing the operation under a set of conditions different from the first set of conditions based at least in part on the simulation.

Method and apparatus for simulating operation in a data processing system

System for distributed task dispatch in multi-application environment based on consensus for load balancing using task partitioning and dynamic grouping of server instance

Techniques are disclosed for synchronizing a primary data system with an auxiliary data system that processes data for the primary data system. In one embodiment, how current the primary data system and the auxiliary data system are is determined. Requests sent from the primary data system that were not processed by the auxiliary data system are determined. The requests are resent to the auxiliary data system for processing.

Synchronizing an auxiliary data system with a primary data system

Provided are techniques for partitioning a physical index into one or more physical partitions; assigning each of the one or more physical partitions to a node in a cluster of nodes; for each received document, assigning an assigned-doc-ID comprising an integer document identifier; and, in response to assigning the assigned-doc-ID to a document, determining a cut-off of assignment of new documents to a current virtual-index-epoch comprising a first set of physical partitions and placing the new documents into a new virtual-index-epoch comprising a second set of physical partitions by inserting each new document to a specific one of the physical partitions in the second set using one or more functions that direct the placement based on one of the assigned-doc-id, a field value derived from a set of fields obtained from the document, and a combination of the assigned-doc-id and the field value.

Index partition maintenance over monotonically addressed document sequences

A method and system for providing convergence of data copies in asynchronous data replication in a database system, includes: labeling rows, a copy of identification and propagation controls. In applying communicated changes, conflicting changes are identified and resolved. In this manner, convergence of data copies in asynchronous data replication is provided, and processing and storage costs are significantly reduced.

Asynchronous peer-to-peer data replication

A computer readable medium encoded with a computer program for handling transaction messages in asynchronous data replication in a database system is disclosed. The computer program provides a high speed parallel apply of transactional changes to a target node such that the parallel nature of the application of changes does not compromise the integrity of the data. The computer program detects, tracks, and handles dependencies between transaction messages to be applied to the target node. If a transaction message has a dependency on one or more preceding transaction messages whose applications have not yet completed, that transaction message is held until the application completes. In addition, the computer program requires significantly less overhead than conventional approaches.

Parallel apply processing in data replication with preservation of transaction integrity and source ordering of dependent updates

A first log reader publishes first messages to a plurality of queues. The messages comprise changes for transactions extracted from a log by the first log reader. In response to one of the queues becoming unavailable, a second log reader is launched to read and extract from the log, and to publish second messages comprising changes for transactions extracted from the log by the second log reader to the unavailable queue as a catch-up queue. In response to the catch-up queue becoming available and the second log reader reaching the end of the log, the publishing of the second messages for the catch-up queue is transferred from the second log reader to the first log reader.

Database log capture that publishes transactions to multiple targets to handle unavailable targets by separating the publishing of subscriptions and subsequently recombining the publishing

Database management systems, methods, and program products that exploit time dependent sequential database management system processes to ensure presentation of the same data or view to one or a plurality of users through sequencing asynchronous database management operations such as recovery and replication. Sequencing is accomplished through the use of entries in sequential logs, including transaction logs, recovery logs, and other data recovery tools and applications. Uses include managing data migration and data replication.

Method, system, and program product for sequential coordination of external database application events with asynchronous internal database events

Database management systems and program products that exploit time dependent sequential database management system processes to ensure presentation of the same data or view to one or a plurality of users through sequencing asynchronous database management operations such as recovery and replication. Sequencing is accomplished through the use of entries in sequential logs, including transaction logs, recovery logs, and other data recovery tools and applications. Uses include managing data migration and data replication.

System and program product for sequential coordination of external database application events with asynchronous internal database events

An information retrieval system and method are provided for minimizing the number of blocks searched in a cell before recording a new record in the table and determining which block can be assigned if a table has space available to store a new record in the case an additional block should be associated with a cell. Dimensions for a table are identified, and at least one block in the table is associated with a dimension value for each dimension, where each block comprises contiguous storage pages. The block can be further associated with a cell; this associated cell has a unique combination of dimension values comprising an dimension value for each of the dimensions. A unique associated bit list for each dimension value for each dimension has a unique corresponding list entry for each block associated with that dimension value, and a unique associated bit list for each cell has a unique corresponding list entry for each block associated with that cell.

System and method for space management of multidimensionally clustered tables

A method masking data failures, when a master copy of data is unavailable comprises storing a single master copy of data and a replica copy of the data; writing to the master using a middleware component; and reading from either the master or the replica using the middleware component, when the master copy is unavailable. When the master is unavailable, the writes are stored in a table located in the middleware component as stored write requests, in which the stored write requests comprise UDI's to be made to the master. The reads are also performed from the table and the replica when the master is unavailable. When the master becomes available, the stored write requests are propagated to the master. Thus, the middleware allows the writes to run during times when the master is unavailable.

Failure transparency for update applications under single-master configuration

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San Jose, CA, United States of America

Bruce Gilbert Lindsay