International Business Machines Corporation

Huawei Technologies Co., Limited

Sherman Lau

Bishwaranjan Bhattacharjee

Timothy Ray Malkemus

George Andrei Mihaila

Lipyeow Lim

Yuk Kuen Chan

Huaxin Zhang

Ronen Grosman

Sean W McKeough

Ping Chen

Cathy McArthur

Reza Sherkat

Zoltan G Toth

Jo-anne Mona Louise Kirton

Kristian Robert Lejao

Tian Chen Gu

Methods, systems, and computer-readable media are described in which WAL records are replayed serially at the database sub-object level, thereby enabling parallelism for processes affecting a single database object without interfering with the consistency required to maintain ROS capability. WAL records are replayed serially at the B-Tree branch level, instead of existing approaches which serialize WAL record replay at the object or block level. Described examples may thereby enable multi-block operations (e.g., SPLIT) within the same B-Tree branch to be replayed in the correct sequence, thereby maintaining consistent reads during ROS. Multi-level dispatching at the object and sub-object levels may be used to minimize delays caused by operations affecting multiple branches of a database object.

Method, database host, and medium for database b-tree branch locking

Generating, by a first primary site that is included in a group of primary sites of a distributed database system, a commit action redo log message for a commit action performed by the first primary site for a first database transaction, the commit action redo log message including a transaction ID for the first database transaction and a transaction order indicator that represents an order of database transactions in a group of database transactions performed at one or more primary sites of the group of primary sites; and sending, by the first primary site, the commit action redo log message, for a corresponding first standby site that backs up the first primary site.

Distributed database remote backup

A method, information processing system, and computer program storage product to compress sorted values. At least a first prefix and a second prefix in a plurality of prefixes are compared. Each prefix comprises at least a portion of a plurality of sorted values. A respective prefix comprises a set of consecutive characters including at least a first character of a respective sorted value. The respective sorted value further comprising a respective suffix comprising consecutive characters of the respective sorted value that are after the respective prefix. At least a respective first character of the first prefix and a respective first character of the second prefix are determined to be substantially identical. The first prefix is merged with the second prefix into a single prefix comprising the first character. A set of suffixes associated with the first prefix is updated to reflect an association with the second prefix.

Compression of sorted value indexes using common prefixes

A method and system utilizes a hierarchical bitmap structure to represent deleted data sets. Each level in the hierarchical bitmap structure may have progressively larger size and represent finer granularity of number of data blocks than its parent level. A method in one aspect may comprise allocating a first level bitmap having size equal to a register on a processor, each bit in the first level bitmap representing a plurality of blocks of data in a database, and allocating one or more pointers corresponding to said plurality of bits in the first level bitmap, said one or more pointers being allocated to point to a sub bitmap generated after a data block is deleted but before the index corresponding to the data block is cleaned.

Method and system for utilizing a hierarchical bitmap structure to provide a fast and reliable mechanism to represent large deleted data sets in relational databases

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Markham, Canada

Sherman Lau