• Journal of Industrial Technology
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• v.15
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• pp.51-62
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• 1995

Databases can crash due to various failures in computer systems. Recovery is a mechanism for restoring consistent data from damages caused by the by the failures and is an essential feature in database systems. This paper surveys recovery techniques for memory resident database systems. We first describe the basic architecture for memory resident database systems, and point out the main factors affecting their performance enhancement. Next, we explain the write-ahead logging(WAL), a recovery technique widely-used in most disk resident database systems, for easy understanding of basic recovery mechanisms. And then, we discuss some new concepts employed in memory resident database systems recovery. Finally, we present a representative memory resident database recovery technique, which is based on a special purpose hardware called HALO, as a case study.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.3
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• pp.1557-1569
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• 2017

In recent times, the Internet of Things (IoT) has rapidly emerged as one of the most influential information and communication technologies (ICT). The various constituents of the IoT together offer novel technological opportunities by facilitating the so-called "hyper-connected world." The fundamental tasks that need to be performed to provide such a function involve the transceiving, storing, and analyzing of digital data. However, it is challenging to handle voluminous data with IoT devices because such devices generally lack sufficient computational capability. In this study, we examine the IoT from the perspective of security and digital forensics. SQLite is a light-weight database management system (DBMS) used in many IoT applications that stores private information. This information can be used in digital forensics as evidence. However, it is difficult to obtain critical evidence from IoT devices because the digital data stored in these devices is frequently deleted or updated. To address this issue, we propose Schema Pattern-based Recovery (SPaRe), an SQLite recovery scheme that leverages the pattern of a database schema. In particular, SPaRe exhaustively explores an SQLite database file and identifies all schematic patterns of a database record. We implemented SPaRe on an iPhone 6 running iOS 7 in order to test its performance. The results confirmed that SPaRe recovers an SQLite record at a high recovery rate.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.23 no.5
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• pp.947-955
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• 2013

Most of the enterprise information is stored in the database. Therefore, in order to investigate the company's criminal behavior, forensic analysis is important for the database and delete record is a need to develop recovery techniques. This paper is explained structure of the oracle database tablespace file and analyzed system tables that stored table information. Further, we suggests a method of recovery for deleted record in oracle tablespace.

• Journal of KIISE:Databases
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• v.31 no.4
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• pp.409-421
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• 2004

A database sharing system (DSS) couples a number of computing nodes for high performance transaction processing, and each node in DSS shares database at the disk level. In case of node failures in DSS, database recovery algorithms are required to recover the database in a consistent state. A database recovery process in DSS takes rather longer time compared with single database systems, since it should include merging of discrete log records in several nodes and perform REDO tasks using the merged lo9 records. In this paper, we propose a two version caching (2VC) algorithm that improves the cache fusion algorithm introduced in Oracle 9i Real Application Cluster (ORAC). The 2VC algorithm can achieve faster database recovery by eliminating the use of merged log records in case of single node failure. Furthermore, it can improve the performance of normal transaction processing by reducing the amount of unnecessary disk force overhead that occurs in ORAC.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.22 no.9
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• pp.1867-1879
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• 1997

DREAM-S is a distributed main-memory database system for the real-time processing of shared operational datra in ATM switching systems. DREAM-S has a client-server architecture in which only the server has the diskstorage, and provides the T-Tree index structure for efficient accesses to the data. We propose a recovery technique for the T-Tree index structre in DREAM-S. Although main-memory database system offer efficient access performance, the database int he main-memory may be broken when system failure such as database transaction failure or power failure occurs. Therfore, a recovery technique that recovers the database (including index structures) is essential for fault tolerant ATM switching systems. Proposed recovery technique relieves the bottleneck of the server processors disk operations by maintaining the T-Tree index structure only in the main-memory. In addition, fast recovery is guaranteed even in large number of client systems since the T-Tree index structure(s) in each system can be recovered cncurrently.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.25 no.5
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• pp.1143-1151
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• 2015

Extensible Storage Engine (ESE) database is a database developed by Microsoft. This database is used in web browser like Internet Explorer, Spartan and in Windows system with Windows Search, System Resource Usage Monitor. Previous ESE database viewer can display an incorrect result and can't read the file depending on collected environment and status of files. And the deleted record recovery tool is limited to some program and cannot recover all tables. This paper suggests the universal recovery method for deleted records and presents the experimental results through development of tool.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.26 no.1
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• pp.125-134
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• 2016

MySQL database is currently used by many users and It has gained a big market share in the database market. Even though MyISAM storage engine was used as a default storage engine before, but records recovery method does not existed. Deleted records have a high possibility for important evidence and it is almost impossible to determine that investigators manually examine large amounts of database directly. This paper suggests the universal recovery method for deleted records and presents the experimental results.

• KIPS Transactions on Computer and Communication Systems
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• v.5 no.5
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• pp.117-126
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• 2016

Recently, increasing utilization of Big Data or Social Network Service involves the increases in demand for NoSQL Database that overcomes the limitations of existing relational database. A forensic examination of Relational Database has steadily researched in terms of Digital Forensics. In contrast, the forensic examination of NoSQL Database is rarely studied. In this paper, We introduce Redis (which is) based on Key-Value Store NoSQL Database, and research the collection and analysis of forensic artifacts then propose recovery method of deleted data. Also we developed a recovery tool, it will be verified our recovery algorithm.

• The KIPS Transactions:PartD
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• v.9D no.6
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• pp.1097-1104
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• 2002

Recently, with a drop in memory chip price and rapid development of mass storage memory chip technology, research on client-server Database Management Systems has gained wide attention. This Paper discusses the recovery technique in a page-server OODBMS environment. Although most researchers have studied client-server systems, the recovery technique has been a poor researches. In this paper, client transfers only the completed log records to the server and resolves the problems in the current recovery techniques. In addition, the server manages only the execution of completed log records suggesting a simple recover algorithm, Client uses system concurrency, fully, by acting to abort actions and it suggests a page unit recovery technique to reduce time that is required in the whole database.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.10
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• pp.4786-4793
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• 2012

In a recent mobile computing environment, the research for a transaction model have been actively carried out to deal with real-time transaction. However, the research for recovery model is relatively insufficient. Therefore, it would be very important for mobile recovery methods for database stability, just in case of data loss due to hand-off in mobile computing system. So, further efficient research should be keenly done to reduce I/O hand-off in mobile computing systems. SLL method increases I/O time due to sequential file. This paper have been suggested to efficient mobile recovery method in mobile computing system. Finally, it has been clearly demonstrated for system efficiency, conducting the performance assessment that currently proposed recovery system.