• Journal of KIISE:Databases
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• v.36 no.5
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• pp.399-404
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• 2009

In a multiple-server DBMS using the share-disk model, when a server process updates data, the updated ones are not immediately reflected to the buffers of the other server processes. Thus, the other server processes may read invalid data. In this paper, we propose a novel method to solve this problem. In this method the server process stores the identifiers and timestamps of the pages that have been updated during a transaction into the coherency volume when the transaction commits. Then, the server process invalidates its buffers of the pages updated by the other server processes by accessing the coherency volume when the lock is acquired, and, subsequently, read the up-to-date versions of the pages from disk. This method needs only a very small coherency volume and shows a good performance because the amount of data that need to be accessed is very small.

• The Transactions of the Korea Information Processing Society
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• v.7 no.2
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• pp.488-496
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• 2000

this paper describes the design and implementation of node scheduling for MX Server that is CC-NUMA System COMSIX, the operating system of MX Server, is designed to suit for CC-NUMA Architecture. MX Server consists of up to 8 nodes, and each node is connected by SCI ring. This node scheduling scheme considers data locality for performance improvement of Oracle8i DBMS on the CC-NUMA architecture. For DBMS such as Oracle8i, a multi-threaded process may be run to tie on particular disk. We have developed a CG binding function that the multi-threaded process bound the node. Currently, We don't have an available CC-NUMA Platform. Instead of MX Server, we developed the Node scheduling scheme for multi-threaded process to suit server platform on the PC test-bed and tested completely.

• Journal of KIISE:Databases
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• v.31 no.5
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• pp.457-467
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• 2004

The efficiency of algorithms managing data caches has a major impact on the performance of systems that utilize client-side data caching. In these systems, two versions of data can be maintained without an additional space overhead of the server by exploiting the replication of data in the server's buffer and clients' caches. In this paper, we present a new cache consistency algorithm employing versions: Two Versions-Callback Locking (2V-CBL). Our experimental results indicate that 2V-CBL provides good performance, particularly outperforms a leading cache consistency algorithm, Asynchronous Avoidance-based Gache Consistency, when some clients run only read-only transactions.

• The KIPS Transactions:PartD
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• v.11D no.1
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• pp.143-152
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• 2004

Recently, software programming method based on EJB for object oriented software design and implement has been used frequently. Usually, case that use permanent data that use Database in EJB base application is most. Part connected with Database-Access that take charge in Entity Bean class of server side creation program. In this paper using J2EE relationship DAO pattern class each separate. This is no much difference with existent pattern method, but in same pattern common classes are designed so that composition may be possible. And as well as use Entity Bean class that created each DBMS classes are different, is doing Rata Source so that connection work is available without alteration or creation of additional program in several DBMS environments.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• autumn
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• pp.143-148
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• 2001

Digital documentation is now becoming a must throughout a building process including design, construction, inspection, procurement and even facility management. The Internet is a backbone of such process, and web-based information exchange is the standard among other mainstream technologies. The current information management techniques, however, is heavily dependant on the server-side processing, which naturally results in the overload of the overall system. This paper proposes an XML-based approach in order to resolve such problems. A VE system was developed to demonstrate the efficiency of the XML solution, in term of efficient VE data management and fast decision making. also in this paper suggests 1) introduce XML based DBMS to improve data management efficiency and 2) introduce Mobile Computing to improve data accessibilities on sites.