公开(公告)号：US20240362192A1

公开(公告)日：2024-10-31

申请号：US18440999

申请日：2024-02-14

Applicant: Hitachi, Ltd.

Inventor： Yoshiki KUROKAWA ,  Toshihiko KASHIYAMA ,  Norifumi NISHIKAWA ,  Mayuko OZAWA ,  Kazuhiko MOGI

IPC: G06F16/182 ,  G06F16/14 ,  G06F16/172 ,  G06F16/18 ,  G06F16/188

CPC classification number: G06F16/1844 ,  G06F16/144 ,  G06F16/172 ,  G06F16/1865 ,  G06F16/188

Abstract: An update method in which a computer updates data stored in a first storage device by copying a plurality of files stored in the first storage device to a second storage device and writing the files updated in the second storage device back to the first storage device, the plurality of files constituting a part of a database. The update method includes a query determination for determining whether a query for requesting writing to one of the files stored in the second storage device is based on a cluster key of the database, low-frequency file identification for identifying a file having a low writing frequency among the files stored in the second storage device, and write-back for writing the file having the low writing frequency identified in the low-frequency file identification to the first storage device.

公开(公告)号：US20170293644A1

公开(公告)日：2017-10-12

申请号：US15508019

申请日：2015-03-27

Applicant: Hitachi, Ltd.

Inventor： Yoshiki KUROKAWA ,  Satoru WATANABE ,  Yoshitaka TSUJIMOTO

IPC: G06F17/30

CPC classification number: G06F16/221 ,  G06F16/21 ,  G06F16/23 ,  G06F16/24542 ,  G06F16/24561 ,  G06F16/28

Abstract: A storage device for storing a column store database, the storage device comprising: a column read unit which reads page data to be searched that have been read from the column store database, acquires a leading row number included in the page data, and reads each column of data in the page data, sequentially from the leading row number to the last row in the column of data; a data search unit which compares each row in each read column of data with first search criteria, from the first row to the last row, and outputs a comparison result; and a search result aggregation unit which, when a comparison result for a range of columns specified by a search request has been output, compares each row in the comparison result with second search criteria, and determines one or more rows in the comparison result that satisfy the second search criteria.

公开(公告)号：US20170286507A1

公开(公告)日：2017-10-05

申请号：US15511223

申请日：2015-07-22

Applicant: Hitachi, Ltd.

Inventor： Koji HOSOGI ,  Mitsuhiro OKADA ,  Akifumi SUZUKI ,  Shimpei NOMURA ,  Kazuhisa FUJIMOTO ,  Satoru WATANABE ,  Yoshiki KUROKAWA ,  Yoshitaka TSUJIMOTO

IPC: G06F17/30

CPC classification number: G06F16/256 ,  G06F16/245 ,  G06F16/90335

Abstract: A database search system receives a command and searches for data, which meets a search condition specified on the basis of the received command, in a whole database which is a database as an entity. The database search system generates a virtual database which is a list of address pointers to the found data and stores the generated virtual database.