International Business Machines Corporation

Vilho T Raatikka

Jarmo Parkkinen

Petri Uolevi Soini

Antoni Wolski

Jarmo K Ruuth

Markku J Manner

Simo A Neuvonen

Jan P Lindstrom

Kyosti M Laiho

Embodiments relate to a method, system, and computer program product for data management. An aspect includes a search index that is created for a database. The search index has a reference value of a first or a second type associating data to a storage location in a first memory or a second memory respectively. Responsive to a data retrieval request, data is accessed using the reference value from the first or the second memory. If there is a data migration between the first and second memory storage, the reference values are then recalculated and altered in the search index accordingly.

Hybrid table implementation by using buffer pool as permanent in-memory storage for memory-resident data

A method, and corresponding computer program product and computer system, for replicating a database image in a distributed database environment comprises: defining a checkpoint image of the primary node including a database structure and a plurality of database pages; creating a replica database by initiating a backup node and saving the defined structure on the initiated backup node; sending each database page of the checkpoint image for saving on the backup node; saving every transaction on the primary node and creating a corresponding REDO transaction; identifying each data page operated on by each REDO transaction; sending each created REDO transaction to the backup node in the order in which the corresponding transaction occurred, and prioritizing each identified database page so that it arrives at the backup node before or substantially at the same time as a corresponding REDO transaction.

Replication for on-line hot-standby database

Providing an index for a database table that includes a first portion of rows stored in a memory device and a second portion of rows stored in a disk device. A request is received relating to a specific row of the database table. An index that includes entries for each row of the database table stored in the memory device and entries for a subset of the rows of the database table stored in the disk device is accessed. A connection is made to the memory device if the specific row is stored in the memory device, and a connection is made to the disk device if the specific row is stored in the disk device. An action related to the specific row is performed based on the received request.

Index for hybrid database

Operating a database system comprises: storing a database table comprising a plurality of rows, each row comprising a key value and one or more attributes; storing a primary index for the database table, the primary index comprising a plurality of leaf nodes, each leaf node comprising one or more key values and respective memory addresses, each memory address defining the storage location of the respective key value; creating a new leaf node comprising one or more key values and respective memory addresses; performing a memory allocation analysis based upon the lowest key value of the new leaf node to identify a non-full memory page storing a leaf node whose lowest key value is similar to the lowest key value of the new leaf node; and storing the new leaf node in the identified non-full memory page.

Prefix-based leaf node storage for database system

Additional information is provided in a checkpoint image such that direct pointers can be included in the checkpoint image. Thus, an in-memory database management system can be restored from the checkpoint image in the event of a failure without causing any significant performance drawbacks to the database management system.

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Espoo, Finland

Vilho T Raatikka