Teradata Us, Inc.

Ncr Corporation

Frederick Stuart Kaufmann

Paul Laurence Sinclair

Louis Martin Burger

Donald Raymond Pederson

Philip Jason Benton

Srinath Boppudi

Tirunagari Venkata Rama Krishna

Grace Kwan-On Au

Chi Kim Hoang

James J Chen

Rolf G&uuml;nter Erich Stegelmann

Mark Anthony Hodgens

Rajendran Kolandasamy

Venkata Ramakrishna Tirunagari

A table reconfiguration command is received. A READ lock is placed on the table while original table data for the table is moved from a first network location to a second network location into a temporary table according to a new map for the table. An EXCLUSIVE lock on the table is obtained, a data dictionary is modified with the new map for the table, the original table data at the first network location is deleted, and the temporary table is renamed to be the table at the second network location; then, the EXCLUSIVE lock is released.

Online and dynamic table reconfiguration

Database processing engines of a single cluster are configured such that each engine is a primary engine and a dedicated fallback engine to one other engine of the cluster. In an embodiment, the cluster includes more than two processing engines.

Dedicated fallback processing for a distributed data warehouse

Data portions of a database can be grouped and ranked in order of priory for reassignment from one or more maps to another one or more maps. It should be noted that a first map can assign the data portions to a first configuration of processors for processing the data portions, and a second map assigns the data portions to a second configuration of processors, different than the first configuration, for processing the data portions in a database system and/or environment. The data portions are reassigned in groups during an available time (window) for reassignment by taking the first one of the groups can be reassigned ('moved') in the available, then the second one in the available reaming time, and so on, until no group of data portions can be moved in the remaining time or all of them have been moved.

Timing of reassignment of data to different configurations of processing units in database systems

Data of a database (e.g., database tables) can be reassigned from a first map to a second map in a database system that uses maps to assign data for processing to multiple processing units of a database system in accordance with one or more distributions schemes. Data portions can be selected in groups and moved in the selected groups in an efficient manner. The selection and/or movement of the data portions can be automated without requiring input for users of database systems.

Management of intelligent data assignments for database systems with multiple processing units

The number of processors that store data can be limited for some data in order to improve efficiency in database system that uses multiple processing units to process data. For example, a map can be provided for one or more sparse database tables (or tables) that are relatively small in view of the number of processors that are available. The map can effectively assign distinct portions of the data, e.g., rows of a database, for processing only to a limited number of processors (or processing units). The database system can use the map to process data accordingly.

Management of sparse data for database systems with multiple processing units

An order (or priority) for reassigning data portions of a database from a first map to a second map can be determined. It should be noted that the first map assigns the data portions to a first configuration of processors for processing the data portions, and the second map assigns the data portions to a second configuration of processors, different than the first configuration, for processing the data portions in a database system and/or environment. The order can be determined by grouping the data in multiple groups and ordering the groups in accordance with a determined priority for reassignment. In doing so, one or more relationships between the data portions and/or cost of use for each one the groups can be considered.

Reassignment of data to different configurations of processing units in database systems

A method for processing a trigger are described. The trigger is associated with a subject table in a relational database and defines a triggering statement and one or more triggered actions. The method includes determining that a triggering statement of a trigger will execute on a subject table row of a subject table and requesting a transition table in response to determining that the triggering statement will execute. The transition table includes a transition table row. The transition table row includes a first value associated with the subject table row and a second value associated with the subject table row. The method further includes reading the transition table row from the transition table and identifying a processing unit to receive the transition table row and a triggered action of the trigger. The method also includes transmitting the transition table row and the triggered action to the identified processing unit to be processed.

Row triggers

A method, apparatus, and article of manufacture for accessing a subject table in a computer system. The subject table is partitioned across a plurality of processing units of the computer system. A trigger is defined for the subject table, such that when a triggering event occurs on the subject table, a triggered action is performed. Both the triggering event and triggered action can be performed in parallel by the computer system. A spool table is generated for each partition of the subject table, wherein the spool table stores one or more necessary records accessed from the subject table by the triggering event. In this manner, triggered actions that refer to these necessary rows need not access the subject table again.

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Irvine, CA, United States of America

Frederick Stuart Kaufmann