International Business Machines Corporation

Other

Rocket Software, Inc.

James Z Teng

Inderpal Singh Narang

Namik Hrle

Chandrasekaran Mohan

Jeffrey William Josten

Serge Bourbonnais

You-Chin Gene Fuh

Donald J Haderle

Craig Alan Friske

Robert William Lyle

Bryan Frederick Smith

Paramesh Sampatrai Desai

Laura Michiko Kunioka-Weis

Johannes Schuetzner

Regina J Liu

Tina L Masatani

Jing Cheng

David B Petersen

Julie Ann Watts

Gautam Bhargava

Jay A Yothers

Tina Louise Mukai

Austin F M D'Costa

Miao Zheng

Ka Chun Ng

Binghui Zhong

Tyrone Yu

Szu-Huey Chuang

Kou Horng Yang

Hong Jing Ying

Yun Yu Wang

Curt Lee Cotner

Terence Patrick Purcell

Thomas Abel Beavin

James Alan Ruddy

Fen-Ling Lin

David R Schwartz

Tanya Couch

John Marland Garth

Jeffrey Allen Berger

Donald Francis Ferguson

Akira Shibamiya

Hong Sang Tie

Jen-Yao Chung

Tammie Dang

William Robert Bireley

Karelle Lynne Cornwell

Guenter Briam

Richard A Crus

Gary Howard Sockut

Stephen Walter Turnbaugh

Jerome Quan Wong

Kathryn Ruth Zeidenstein

George W Wang

Maureen Mae McDevitt

David Warner

Christos Nicholas Nikolaou

Ramani M Croisettier

A system for providing continuous availability comprises a second computing site that is geographically remote from a first computing site. The second computing site comprises a storage unit configured to store units of work data and data synchronously replicated from the first computing site. The second computing site further comprises a group of workloads configured to process the units of work data asynchronously replicated from the first computing site. The second computing site further comprises a software replication module configured not to replicate any data while the first computing site is available.

Zero-data loss recovery for active-active sites configurations

Methods and apparatus, including computer program products, for maintaining a set of indexes in a database management system (DBMS) having at least one table. A current, stale or deferred status is defined for at least a part of the indexes, resulting in at least a part of a set of current, stale, or deferred indexes in the DBMS. Current indexes are maintained by refreshing a current index synchronously with a table change relating to the current index. Stale indexes are maintained by refreshing a stale index continuously and asynchronously to table modifications of tables relating to the stale index based on log information relating to the modifications. Deferred indexes are maintained by building a deferred index in response to a query to a table relating to the deferred index, thereby bringing the deferred index in accordance with the current query time status to the table relating to the deferred index.

Automatic maintenance of a set of indexes with different currency characteristics in a database management system

Techniques for restoring point-in-time and transaction consistency across consistency groups between a first and a second independent database management system (DBMS) for a disaster recovery. Several consistency groups (CGs) are defined for replication. For each CG in the first DBMS data changes are transmitted to a second DBMS. A timestamp representing a most recently received commit log record or a heartbeat during periods of inactivity for a CG is stored in a database table at regular intervals. At regular intervals, the timestamp is compared with timestamps for other CGs to identify a common time at which data to be applied to the CGs in the second DBMS have been received into a recoverable data store. The received data is applied to the CGs in the second DBMS up to the common time.

Restoring database consistency integrity

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.

Prefetching data using a piecemeal list prefetching method. This is achieved by various means, including building a plurality of data pages, sorting the plurality of data pages into sequential data pages and a list of non-sequential pages, prefetching the sequential data pages using a first prefetching technique, and prefetching the non-sequential list of data pages using a second prefetching technique.

Piecemeal list prefetch

According to one embodiment of the present invention, a method for identifying relevant database indexes is provided. According to one embodiment of the present invention, a method includes determining the importance of a particular database transaction and storing an index name related to the transaction along with an indicator of the importance. A database transaction is initiated and the importance indicator is received in an index advisor. The index advisor then makes an index recommendation based on the index importance.

Enhanced identification of relevant database indices

A system for controlling concurrency of access to data in a database system is provided. The system includes receiving a lock request for access to data in the database system, in which the lock request is a request for a page lock or a row lock for a corresponding row or page in the database system containing the data. The method further includes identifying a partition in the database system that contains the row or the page in the database system containing the data; associating the lock request with a partition lock on the partition that contains the row or the page in the database system containing the data; and accessing the data using the partition lock.

System for controlling concurrent access to data in a database system

A computer system and a relational database management system (RDMS) computer program product are described for interfacing a number of concurrently running database sessions with a large database in which a plurality of local temporary object database descriptors are used in lieu of a single global temporary object database descriptor where the global and each of the local temporary object database descriptors include identifiers for temporary objects, each of the local temporary object database descriptors is associated with a single database session and each of the global database descriptors is shared among multiple database sessions.

Computer program product and method for database management system supporting multiple temporary tables

A method of searching a data page in a table space of a database for inserting a data record to a first table, wherein the table space comprises space map pages and sets of data pages, wherein each space map page comprises information about the available storage space of one set of data pages, wherein each space map page and the corresponding set of data pages is further assigned to a table range for each table to which at least one data page in the set of data pages belongs to, wherein the database further comprises a clustering index for the first table in the database management system, wherein the database management system comprises a space usage information database, and wherein the space usage information database holds space usage information for each table range.

Method for searching a data page for inserting a data record

According to the method for establishing a log point an information technology infrastructure is provided. Transactions are performed by at least two database units of the information technology infrastructure. Then, 'suspending prepare to commit'-requests are sent from said coordinating device to said database units. The log writes of all database units are suspended and recorded, whereas these log points form a global log point. Finally the log writes of all database units and all the suspended transactions are resumed.

Method and information technology infrastructure for establishing a log point for automatic recovery of federated databases to a prior point in time

A method, apparatus, and article of manufacture accesses a dataset using an unsupported access method. A first request to access a dataset is intercepted. The first request is associated with a first data structure that specifies a first access method. The first data structure is replaced with a second data structure that specifies a second access method which is different from the first access method. The dataset is accessed in accordance with the second access method of the second data structure. In another particular embodiment, the first access method is the basic direct access method, and the second access method is any of the basic sequential access method and the queued sequential access method. In yet another embodiment, the dataset is an extended format physical sequential dataset.

Accessing a dataset using an unsupported access method

The present invention is related to a method and system for preserving an original table schema for a table in a database system that supports dynamic table schema changes. The method and system includes storing the original table schema for the table in a designated table prior to performing a schema change on the table. By storing the original table schema in the designated table, a backup copy of the table that includes rows which are not self-describing can be used for data recovery.

Method and system for preserving an original table schema

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San Jose, CA, United States of America

James Z Teng