International Business Machines Corporation

Dirk Nakott

Jens Peter Seifert

Thomas Rech

Holger Hellmuth

Alexander Zietlow

Martin Jungfer

Hans-Jürgen Zeltwanger

Karl Fleckenstein

Andrei Fedorovich Lurie

Johannes Schuetzner

Oliver Harm

Gunter Schoellmann

Jörn Klauke

An approach includes collecting metadata indicative of a computer system comprising (i) a primary database, configured to connect to a secondary database, and (ii) the secondary database that replicates the primary database. The approach further includes receiving, at the primary database from a requestor, a query referencing the primary database. The approach further includes, responsive to receiving the query, performing an offload including: determining a first load on the primary database; responsive to the first load satisfying a first offload condition, determining, using the metadata, whether a second load on the secondary database satisfies a second offload condition; and responsive to the second load satisfying the second offload condition, offloading at least part of the query to the secondary database in order to cause the at least part of the query to be executed by the secondary database. The method further includes providing to the requestor results of the query.

Query offloading in a computer system

A system and method for a database management system. The method comprises: receiving a database transaction for inserting a set of records in a database table of the database management system or for creating indexes. The database transaction may be executed using the database management system. The database management system may rollback the database transaction by truncating the database table or the created indexes.

Rolling back a database transaction

A method for generating a copy of a database using a data streaming protocol is disclosed. The method comprises setting up a structure of a secondary database, prioritizing data objects to be copied from a primary database to the secondary database, copying data objects from the primary database to the secondary database using a data streaming protocol, restoring data corresponding to the data object in the secondary database in parallel to copying data objects from the primary database to the secondary database, applying changes made to the data corresponding to the data object in the primary database during the time of copying, after the data object has been copied, and making available the secondary database for usage once all data objects have been copied from the primary database to the secondary database so that a usable copy of the primary database is created.

Efficient creation of a secondary database system

A tool for replacing a first database node of a database management system by a second database node. The tool receives an indication that the first database node received a data access request for accessing a database shared between the first database node and the second database node. The tool duplicates the data access request at the first database node. Responsive to a determination that the duplicated data access request includes a data changing statement and a previously executed statement, the tool modifies the duplicated data access request to prevent execution of the data changing statement and the previously executed statement at the second database node. The tool executes the modified duplicated data access request at the second database node. The tool replaces, based on a replacement condition being met, the first database node with the second database node in the database management system.

Managing nodes of a DBMS

Dynamically switching between a plurality of execution paths to execute a function, such as a user-defined function. The plurality of execution paths include an execution path that uses caching and another execution path that uses inlining. A user-defined function is executed at least once using a first execution path. Then, for a later execution of the function, the execution path is automatically switched to a second execution path.

Dynamically switching between execution paths for user-defined functions

A method, system, and computer program product for implementing backup history cleanup operations for a database management system are provided. The method includes identifying a version control base (VCB) value for a most recently stored record in a history table, the record representing a back up copy of a data set. The method includes scanning the table starting from most recently stored records to identify records that represent previous backup copies of the data set, the records assigned VCB values. Using a retention limit value assigned to each of the VCBs, the method includes selecting at least one record to determine the deletion date for use in implementing the cleanup operations. The selection includes counting the number of records, representing back up copies of the data set, for each VCB value; identifying last records for respective VCBs that do not exceed the retention limit value; selecting the oldest storage date among the last records; and deleting records that have storage dates older than the oldest storage date.

Growing community of inventors

Stuttgart, Germany

Dirk Nakott