Hitachi, Ltd.

The University of Tokyo

Hitachi Communication Technologies, Ltd.

Shinji Fujiwara

Nobuo Kawamura

Yoshio Suzuki

Kazuhiko Mogi

Akira Shimizu

Satoru Watanabe

Kazutomo Ushijima

Masaru Kitsuregawa

Kazuo Goda

Seisuke Tokuda

Itaru Nishizawa

Michiko Yoshida

Norifumi Nishikawa

Tsunehiko Baba

Tsuneyuki Imaki

Daisuke Ito

Kazuhiko Mizuno

Michiko Tanaka

Hideomi Idei

Kota Yamaguchi

Mitsuru Nagasaka

Frederico Buchholz Maciel

Tetsuya Uemura

Yooichi Shintani

Nobutoshi Sagawa

Shigekazu Inohara

Takayuki Tsuchida

Akira Yamamoto

Kazuhisa Fujimoto

Manabu Kitamura

Shigeru Matsuo

Hiroyuki Yamada

Naoki Hamanaka

Atsushi Nakamura

Atsushi Sutoh

Yoshimasa Masuoka

Keiro Muro

Akinori Asahara

Yuki Yamada

Kazuo Masai

Akihiko Sakaguchi

Hiroaki Odawara

Masahisa Narita

Sadaki Nakano

Yuto Hayamizu

Hidehito Takewa

Satoshi Katsunuma

Yori Takahashi

Shinsuke Hamada

Mayuko Ozawa

Yoichi Shintani

Mikiko Suzuki

Wataru Kawai

The scanning range of an inner table can be limited in the join processing irrespective of the existence of search conditions or a partition key, and the performance of the join processing can be improved. There is a column range index representing a range of values stored in a table. When a join result of a current stage is an outer table related to a join of a next stage in a join of each stage of the join processing, a database management apparatus identifies whether there is a possibility that an inner table related to a join of a next stage includes a hit record in an inner table related to a join of a current stage based on a column range index corresponding to a join column of a current stage and a column range index corresponding to a join column of a next stage.

Database management apparatus and method

A database is stored in a plurality of pages that are a plurality of logical storage areas constituting a logical storage space. Data writing to a database in the logical storage space is performed in a page unit. A storage control apparatus coupled to an external storage and including a cache device writes data to the cache device in a page unit. The storage control apparatus determines whether an execution condition on external writing that is writing to the external storage is satisfied. When a result of the determination is true, the storage control apparatus writes data stored in the cache device to the external storage in a bulk unit that is larger than a page unit and is a writing unit in which consistency is maintained.

Storage control apparatus and method for a database storing data in pages

A database management system (DBMS) generates a query execution plan including information representing one or more database (DB) operations necessary for executing a query and executes the query based on the query execution plan. In the execution of the query, the DBMS dynamically generates a task for executing a DB operation and executes the dynamically generated task. The DBMS executes a task in a plurality of threads executed by a processor core.

Database management system, computer, and database management method

As an I/O method of issuing an I/O request, there are a synchronous I/O method, in which a task is in a waiting state until an I/O response to the I/O request is returned and an asynchronous I/O method, in which another task can be executed before an I/O response to the I/O request is returned. When issuing an I/O request in execution of a task, a DBMS selects any one of the synchronous I/O method and the asynchronous I/O method, based on an I/O response speed of an I/O destination storage device and issues an I/O request according to the selected I/O method.

A database includes a plurality of data blocks. Each of the plurality of data blocks includes a plurality of data pages in which a plurality of column values recorded in one or more records corresponding to the data block are stored. Each of the plurality of data pages has two or more column values in one column corresponding to the data page stored therein. A database server selects a data block from the plurality of data blocks and specifies a data page to be scanned from the selected data block.

Database management system, database server, and database management method

A storage device, connected to a computer including a processor and first memory, and executing a program, stores data processed under the program. The computer includes a protocol processing unit that accesses data in the storage device, an accelerator that includes an arithmetic unit executing a part of a process of the program, and a second memory storing data, and executes the part of the process. The first memory receives a processing request for processing data, and causes the accelerator to execute a command to process data, corresponding to the processing request for the processing request including a process to be executed by the arithmetic unit. The accelerator requests the protocol processing unit to provide target data indicated by a command received from the program, reads data from the storage device via the protocol processing unit, and stores the data in the second memory. The arithmetic unit executes the command.

Computing system and server

A database management system (DBMS) manages a database existing in a second storage device with an access speed lower than that of a first storage device. In an execution of a query, the DBMS dynamically generates tasks two or more executable tasks in parallel. The DBMS generates task start information which is information representing a content of the execution of the task, manages the task start information, and executes a content represented by the task start information by the task. The task start information includes a data address set existing in the second storage device. The DBMS controls movement of the data address sets between the first storage device and the second storage device based on a management state of the task start information. In addition, the DBMS selects the task start information based on whether or not the data address set exists in the first storage device.

Provided is a database management apparatus, having a processor, a memory, and a storage device, whereby a database which is stored in the storage device is managed, the database management apparatus further comprising: a query acceptance unit which accepts a query to the database; a query execution plan generating unit which generates a query execution plan which includes a database operation which is necessary for executing the accepted query; and a query execution unit which, in executing the accepted query on the basis of the generated query execution plan, dynamically generates a task for executing the database operation, and executes the dynamically generated task. The query execution unit acquires a resource usage state, and, when executing the next database operation, generates a new task on the basis of the resource usage state, and executes the new task in parallel with the task.

Database management apparatus, database management method, and storage medium

There is a storage apparatus which provides a storage area, comprises a cache memory, reads data into the cache memory from the storage area according to a read request and sends the data from the cache memory, and a computer is coupled to the storage apparatus. The computer receives a data processing request, determines an access usage based on the data processing request (or, the information relating to an access usage of the data processing request), selects a logical device corresponding to the determined access usage from a plurality of logical devices which are allocated to the storage area and issues a read request to the selected logical device.

Computer and data read method

A database management system receives a new data table input to a database; and executes unique constraint determination processing of determining whether each comparison-subject value as each value registered in a target column in the new data table is different from each comparison reference value as each value registered in a target column in a stored data table in the database, and stores the new data table in a second database area different from a first database area storing the stored data table in the database when a determination result obtained in the unique constraint determination processing is true.

Database management system and database management method

A management system manages a plurality of data units constituting schemas of a database in a storage device, which includes a plurality of first storage device sets having a plurality of storage areas. An ordered schema constituted of the plurality of data units having order properties defining respective orders is included in the schemas. When a second storage device set, which is a set of one or more second storage devices and in which each of the storage areas is a free storage area, is added to the first storage device set, the management system migrates two or more data units not consecutive in the order among a plurality of data units stored in the plurality of storage areas in the first storage device set respectively from at least the one first storage device set to the free storage areas of the second storage device set.

Management system and management method for managing data units constituting schemas of a database

A database management system (DBMS) generates a query execution plan including information indicating one or more database (DB) operations necessary to execute the query. The DBMS dynamically generates a task for executing the DB operation in execution of the query. The DBMS performs a determination processing of simultaneous-task-generation number when newly creating a task. The determination processing of simultaneous-task-generation number is to calculate the number of simultaneous task generation, which is the number of tasks that can be generated simultaneously, based on the number of tasks which can be newly generated, a first memory resource amount which is the amount of memory resources necessary to be allocated per task newly generated, and a second memory resource amount which is the number of memory resources that can be newly allocated. The number of tasks generated dynamically and simultaneously is equal to or smaller than the calculated number of simultaneously generatable tasks.

A parallel data processing system includes a parallel data processing execution unit for reading a data from a data set including a first data set that includes a plurality of first data and a second data set that includes a plurality of second data and executing processing. The parallel data processing execution unit (A) reads the first data from the first data set, and acquires a first value from the first data based on first format information acquired from an application, (B) generates one or more threads for respectively reading one or more second data corresponding to the first value from the second data set based on first reference information acquired from the application, (C) executes (A) and (B) on one or more first data in the first data set, and (D) executes a plurality of the threads in parallel.

Parallel data processing system, computer, and parallel data processing method

A database management system (DBMS) generates a query execution plan including information representing one or more database (DB) operations necessary for executing a query, and executes the query in accordance with the query execution plan. In the execution of the query, the DBMS dynamically generates tasks for executing the DB operations and executes the dynamically generated tasks. The query execution plan includes a plurality of query blocks, which are sets of one or more DB operations. When newly generating a task, the DBMS executes determination processing of simultaneous-task-generation number. The determination processing of simultaneous-task-generation number is to calculate, targeting each of the query blocks, the number of simultaneous task generation, which is the number of tasks simultaneously generatable as tasks for executing the query block. The number of the dynamically generated tasks is equal to or smaller than the number of simultaneous task generation.

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Sagamihara, Japan

Shinji Fujiwara