Title:
COMPUTER SYSTEM AND DATABASE MANAGEMENT METHOD
Document Type and Number:
WIPO Patent Application WO/2016/162981
Kind Code:
A1
Abstract:
According to the present invention, a write-once nonvolatile storage device for storing at least a portion of a database has extended logical-to-physical conversion information that associates, for each of a plurality of logical addresses, a timestamp, a physical address, and a reference counter with each other. Each reference counter indicates the number of referring sources to the data associated with both the logical address and the timestamp that are associated with the reference counter. On the basis of the extended logical-to-physical conversion information, the write-once nonvolatile storage device determines whether a target logical address has associated therewith a timestamp older than a last timestamp, and if so, determines whether the reference counter associated with both the target logical address and the older timestamp indicates that there is no referring source. If this determination is affirmative, then the write-once nonvolatile storage device manages, as an erasable physical region (invalid physical region), the physical region at the physical address associated with both the target logical address and the older timestamp.
Inventors:
USHIJIMA KAZUTOMO (JP)
YAMAMOTO AKIRA (JP)
YAMAMOTO AKIRA (JP)
Application Number:
PCT/JP2015/061007
Publication Date:
October 13, 2016
Filing Date:
April 08, 2015
Export Citation:
Assignee:
HITACHI LTD (JP)
International Classes:
G06F12/00
Foreign References:
| JP2009282746A | 2009-12-03 | |||
| JP2013541743A | 2013-11-14 |
Attorney, Agent or Firm:
WILLFORT INTERNATIONAL PATENT FIRM (JP)
Patent business corporation Wil photograph international patent firm (JP)
Patent business corporation Wil photograph international patent firm (JP)
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