International Business Machines Corporation

James Zu-Chia Teng

Namik Hrle

Julie Ann Watts

Jeffrey William Josten

Guogen Zhang

Kalpana Shyam

Jay A Yothers

Karelle Lynne Cornwell

Stephen Walter Turnbaugh

Robert William Lyle

Inderpal Singh Narang

You-Chin Gene Fuh

Sauraj Goswami

San Yu Phoenix

Harold Wade Cain, Iii

Jeffrey Mark Nick

David Arlen Elko

Hong Min

David Harold Surman

Donna N Dillenberger

Michel H T Hack

Gong Su

Kelly B Pushong

Akira Shibamiya

Steven Bruce Jones

Qinghua Zou

Michael R Shadduck

Thomas Majithia

William James Franklin

Frank Darl Bower

John Richard Lyle

Saiyin Leung

Balakrishna Raghavendra Iyer

Fen-Ling Lin

Yao-Ching Stephen Chen

Tanya Couch

Bryan Frederick Smith

Jerry Mukai

Jeffrey Allen Berger

Craig Alan Friske

John Joseph Campbell

Laura Michiko Kunioka-Weis

Christopher John Crone

Brian Shaun Vickery

Andreas Maier

Charles Roy Bonner

Margaret Ann Bernal

Gary Howard Sockut

Shyh-Yee Wang

Julie Chen

Hiromi Masuda

Michael John Bracey

Barbara Tanya Couch

Xi Ming Xu

Jeffrey James Todd

Roy J Comford

Haakon Philip Roberts

Jack R Shedden

Roy James Cornford

Systems, methods, and products for database system transaction management are provided herein. One aspect provides for annotating via a computing device at least one data object residing on the computing device utilizing at least one transaction tag, the at least one transaction tag being configured to indicate a status of an associated data object; processing at least one database transaction utilizing a transactional memory process, wherein access to the at least one data object is determined based on the status of the at least one data object; and updating the status of the at least one data object responsive to an attempted access of the at least one data object by the at least one database transaction. Other embodiments and aspects are also described herein.

Database system transaction management

A method, system and computer program product for improving performance of concurrent data inserting provide the features of adding a prefix to each key value in an index, wherein the prefix has a default value, allocating a corresponding prefix to each concurrent inserting process in response to an occurrence of a hot spot mode being detected, wherein each allocated prefix is different from the default value, performing an inserting operation in the hot spot mode, wherein the inserting operation includes deciding whether a key value can be inserted with the default value of the prefix, in response to a determination that an insertion of a key value with the default value of the prefix can be performed, inserting the key value with the default value of the prefix, and in response to a determination that an insertion of a key value with the default value of the prefix cannot be performed, inserting the key value with another prefix allocated by the inserting process.

Performance of concurrent data inserting

A method and system for providing a scalable storage scheme for native hierarchically structured data of relational tables, includes a base table with indicator columns with information pertaining to hierarchically structured data of a document, data tables for storing the hierarchically structured data corresponding to the indicator columns, and node identifier indexes corresponding to the data tables for mapping between the indicator columns and the hierarchically structured data in the data tables. In an embodiment, actual data for each hierarchically structured data (such as XML) column is stored in a separate data table, and each data table has a separate node identifier index. The node identifier index is searched with a key containing the document identifier and a logical node identifier is used, and a record identifier of a record in the data table containing the node assigned the logical node identifier is retrieved.

Scalable storage schemes for native XML column data of relational tables

Provided is a method for online reorganization and increasing the page size of a DB2 object. A base table and related auxiliary table spaces are reorganized concurrently via a database utility, DB2 REORG utility. The database utility determines which auxiliary tables are related to the base table and automatically includes their respective auxiliary table in the same invocation of the utility. The reorganization is performed via allocated shadow data sets; page size of the allocated shadow data sets is dynamically updated during reorganization. The original data sets are switched with the newly built shadow data sets, and DB2 catalog values and control blocks are updated with new page size values.

Method of changing the page size of a DB2 table space while keeping the object available

A new sub-document versioning method for record storages of XML documents which uses virtual cutting points to ensure that a search tree is able to support multiple versions of sub-documents and provide efficient mechanisms for XML updating. Record boundaries and virtual cut points divide the two-dimensional space, the horizontal axis representing node identifiers in document order and vertical axis representing version numbers, into rectangles. The bottom corner of the rectangle is used to represent the rectangles and the corresponding information of the corner is added to the search tree index.

XML sub-document versioning method in XML databases using record storages

A system and method for concurrency control of hierarchically structured data is provided. Lock requests on a target node are processed by exploiting ancestor-descendant information encoded into prefix encoded node identifiers (IDs). A set of implicit locks on ancestor nodes along a path from an immediate parent of a target node to a root node is derived from an explicit lock request on a target node. A logical lock tree describing existing lock modes for ancestor nodes is consulted to determine compatibility with the derived set of implicit locks. If existing lock modes for ancestor nodes are compatible with the derived set of implicit locks, a lock request on a target node is granted. Otherwise, the lock request is denied. A lock release request follows the reverse process; a target node in a particular transaction is released, as are subsequent locks on its ancestors made by the same transaction.

Efficient locking protocol for sub-document concurrency control using prefix encoded node identifiers in XML databases

A system for retrieving stored data and/or index pages, receives a database request, generates an access plan for the database request for accessing data rows and/or index entries according to the statement, and generates a priming process by selecting a set of data and/or index pages. The set of data and/or index pages is a super-set or the exact set of the pages needed for accessing data rows and/or index entries according to the access plan. The present system retrieves the data and/or index pages of the set before executing the database request according to the access plan. The execution of the database request is performed by scanning the index and data pages preloaded into the cache. This reduces the number of necessary disk reads during execution.

System and method for performing just-in-time priming of a database cache

Various embodiments of a computer-implemented method, system and computer program product maintain a logical page having a predetermined size. Data is added to an uncompressed area of the logical page. The uncompressed area of the logical page is associated with an uncompressed area of a physical page. The logical page also has a compressed area associated with a compressed area of a physical page. In response to exhausting the uncompressed area, data in the uncompressed area is included in the compressed area. The uncompressed area is adjusted.

Compressibility checking avoidance

The present system indexes a plurality of entries in a database that contains a database table having a base index. As a recent row is inserted in the database table, an index increment is generated based on the inserted row. Preferably, the index increment is smaller in size than the base index because it is recently generated. The smaller size of the index increment facilitates the management of the index increment. An index entry associated with the inserted row is added to the index increment, and the index increment is merged with the base index.

Incremental indexing of a database table in a database

Various embodiments of a computer-implemented method, system and computer program product are provided. A first plurality of key entries of a first index page are compressed in accordance with an order specified by a first keymap of the first index page. The first keymap also indicates respective positions of the key entries of the first plurality of key entries. A second keymap is generated indicating the order and also indicating respective post-compression positions of the key entries of the first plurality of key entries. The compressed first plurality of key entries is stored on a second index page with the second keymap.

Keymap order compression

A partial index availability system places, in a restricted state, all pages in the index associated with a structure modification, when an error occurs in processing a log of the said structure modification. This maintains traversability of the rest of the index that is not in restricted state. The system locates and marks a left sentinel and a right sentinel associated with a non-leaf page that is in a restricted state preventing an undo of a transaction. The sentinels prevent a transaction from accessing an uncommitted change associated with the non-leaf page. After a recovery procedure is run the entire index is made available. During the period between the placement of the index pages in LPL or rebuild pending to the time of final removal of these pages from their restrictive states as a result of a recovery procedure being run, the users are given access to the non-restricted portion of the index.

System and method for increasing availability of an index

A system, method a computer usable storage medium tangibly embodying a program of instructions executable by the computer to perform a computer-based method for restoration of a database from a failed data recovery. For each failed data recovery the method generates a log error data set having log records of a faulty transaction unapplied to data due to inconsistency. Log error data set is directly useable by a log analysis tool to regenerate and redo the unapplied faulty transaction to recover the data and by a print log tool to diagnose the faulty transaction. Log records mimic format of records of an archive log data set and identify data objects, faulty transactions on the data objects and a range of the unapplied data objects' updates.

System and method for minimizing data outage time and data loss while handling errors detected during recovery

A method and system for controlling concurrency of access to data in a database system, includes: partitioning a table in the database system into a plurality of partitions; receiving a request for access to data; determining a partition of the plurality of partitions that contains the data; determining if the data has been committed; and if so, avoiding locking the partition in response to the request. By avoiding locking the partition when the data has been committed, the number of partition locks that need to be requested from a local resource lock manager is reduced, improving performance.

System and method for selective partition locking

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San Jose, CA, United States of America

James Zu-Chia Teng