International Business Machines Corporation

Ka Chun Ng

Craig Alan Friske

Haakon Roberts

James Z Teng

James Alan Ruddy

John Marland Garth

Laura Michiko Kunioka-Weis

Regina J Liu

Binghui Zhong

Szu-Huey Chuang

Arnold T Banzon

Bituin B Vizconde

Embodiments of the present invention disclose a computer program product for rebalancing partitioned data based, at least in part, on limit key extrapolation in a database and one or more characteristics of the plurality of database partitions. Responsive to a determination that an upper limit key value of the last loaded record is greater than an upper limit key value of an empty partition, the computer redefines the upper limit key value of the empty partition using an extrapolated upper limit key value that is based, at least in part, on a range of limit key values. The computer updates one or more characteristics of the database, wherein the one or more characteristics include one or both of a) an average number of records per partition, and b) an average number of unique limit key values per partition.

Method for rebalancing data partitions

Embodiments of the present invention disclose a method, computer program product, and system for rebalancing partitioned data based, at least in part, on one or more characteristics of the plurality of database partitions. The computer updating characteristics, wherein the one or more characteristics include one or both of a) an average number of records per partition, and b) an average number of unique limit key values per partition. Embodiments of the present invention disclose a method, computer program product, and system for limit key extrapolation in a database. Responsive to a determination that the upper limit key value of the last loaded record is greater than the first upper limit key value of the first empty partition, the computer redefines the first upper limit key value of the first empty partition by an extrapolated upper limit key value based, at least in part, on the range of limit key values.

Recovering data to a point in time before pending definition changes are materialized in a relational database management system. One or more definition changes to a database schema are received. Original data base schema attributes are saved as point in time metadata in a catalog table until the one or more definition changes have been materialized. During recovery processing, it is determined for each object being recovered whether the object is being recovered to a point in time prior to which the one or more definition changes were materialized. In response to determining that an object is being recovered to a point in time prior to which the one or more definition changes were materialized, the saved point in time metadata is used for the object in the recovery process.

Point in time recovery support for pending schema definition changes

Recovering data to a point in time before pending definition changes are materialized in a relational database management system. One or more definition changes to a database schema are received. Original data base schema attributes are saved and maintained as point in time metadata in a catalog table until the one or more definition changes have been materialized. During recovery processing, it is determined for each object being recovered whether the object is being recovered to a point in time prior to which the one or more definition changes were materialized. In response to determining that an object is being recovered to a point in time prior to which the one or more definition changes were materialized, the saved point in time metadata is used for the object in the recovery process.

A method, apparatus and program storage device for managing buffers during online reorganization. An adaptive buffer is provided having a dynamically adjustable boundary, the adaptive buffer processes log records and pointers associated with the log records during online reorganization of a database. Adaptive switching is provided between a first and a second task during the processing of data log records and index log records during the online reorganization of the database.

Method, apparatus and program storage device for managing buffers during online reorganization

A method, apparatus and program storage device for determining an optimal number of tasks during reorganization of a database system with memory and processor constraints. The reorganization system identifies memory constraints, identifies processing capabilities and determines a number of reorganization processes and a combination of reorganization processes that provides a minimum reorganization time based upon the identified memory and processing constraints. The identified memory and processing capabilities identify a domain representing a set of rules applicable to the identified memory and processing capabilities. The set of rules of the identified domain are applied to determine an optimal number and combination of reorganization processes that minimizes a reorganization time.

Method, apparatus and program storage device for determining an optimal number of tasks during reorganization of a database system with memory and processor constraints

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San Jose, CA, United States of America

Ka Chun Ng