International Business Machines Corporation

Bjoern Broll

Knut Stolze

Andreas Brodt

Daniel Martin

Torsten Steinbach

Jens Mueller

Oliver Koeth

Ruiping Li

Sabine Perathoner-Tschaffler

Laura Michiko Kunioka-Weis

Claus Kempfert

Xiaohong Fu

Stefan Renner

A method, system and computer program product for copying data from a source database to a target database. A first database engine of the source database assigns a data-change-ID to each changed row in the source table. The data rows of the source table are stored in a plurality of source pages. Each source page comprises a source-page-ID and a highest-data-change-ID indicating its most recently changed data row. The target table comprises a source-page-ID-column. A second database engine of the target database maintains a metadata table comprising a source-page-ID column and a highest-data-change-ID column. The highest-data-change-IDs in the metadata table are compared with the highest-data-change-IDs of the source pages for selectively copying source table rows of source pages whose highest-data-change-ID is higher than their highest-data-change-ID in the metadata table to the target table.

Copying data changes to a target database

Disclosed herein are methods for receiving a command for adding or removing a resource in a database and acquiring an exclusive lock for the database in response the command. In response to obtaining the exclusive lock, the method comprises determining a first number indicating the number of resources currently existing in the database and a second number indicating the number of resources subject to concurrent further commands for adding or removing a resource; comparing the first and the second number for determining whether the received command will remove the last existing resource or add a first resource to the database; and obtaining an exclusive or a shared lock for the received command in dependence on the determination. The method further includes releasing the exclusive lock for the database and adding or removing the resource while holding the lock obtained for the received command.

Locking concurrent commands in a database management system

An indication of data of a first table in a first database is received. The data includes one or more rows of data. The indicated data is transferred from the first table in the first database component to a backup table in the same database component. The data is transferred from the backup table to a second table in a second database component.

Row-based archiving in database accelerators

A method for archiving a predefined portion of a table residing in a database system includes: creating a first backup copy of the portion of the table; assigning to the portion of the table an access state flag; setting the access state flag; using the access state flag for preventing modification of existing backup copies of the portion of the table and for preventing further backup operations on the portion of the table; archiving the portion of the table to a separate system; deleting the content of the portion of the table from the database system and retaining the access state flag in the database system.

Method and system for a safe archiving of data

The present invention provides database systems configured for creating and utilizing a transactions predictive model using a computer, the database system including: a database management system (DBMS) for handling transactions in the database system, the DBMS including a prediction component for generating the transactions predictive model; a database workload table for capturing commands associated with the transactions, the commands utilized for generating the transactions predictive model; database data for providing data in response to the transactions; and a prediction model database for storing the transactions predictive model, where the prediction component is configured for generating a generalized statement for each statement corresponding with the transactions, identifying a sequence of transactions of the transactions, creating a transaction class based on the sequence of transactions, identifying a current transaction, and then calculating probabilities between transactions, where each statement includes at least a database command.

Transaction prediction modeling method

A method for storing intermediate result sets in a database is provided. An access plan for a single query for accessing data stored in the database system is received. An intermediate result set is generated during execution of the access plan. A value of an intermediate result set rating of the intermediate result set is determined during execution of the access plan at runtime of the query for determining if the intermediate result set, generated during the execution of the access plan, is to be stored. Based on determining that the value of the intermediate result set rating meets a predefined criterion, the determined intermediate result set is stored for a longer period of time than the runtime of the query as a stored intermediate result set.

Intermediate result set caching for a database system

Methods of generating a transactions prediction model using a computer for optimizing a number of transactions associated with a database system include capturing a database workload, where the database workload includes a number of statements corresponding with the transactions over a specified period of time, where each of the statements includes a variable parameter; then generating a generalized statements from the statements by replacing the variable parameter with a constant value; then generating other generalized statements, where if two or more of the number of the generalized statements are the same grouping the generalized statements to correspond with the other generalized statements; and then creating transaction classes, where each of the transaction classes includes at least one generalized statements.

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Waldenbuch, Germany

Bjoern Broll