• Title/Summary/Keyword: Index Update

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An Efficient Technique for Processing Frequent Updates in the R-tree (R-트리에서 빈번한 변경 질의 처리를 위한 효율적인 기법)

  • 권동섭;이상준;이석호
    • Journal of KIISE:Databases
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    • v.31 no.3
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    • pp.261-273
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    • 2004
  • Advances in information and communication technologies have been creating new classes of applications in the area of databases. For example, in moving object databases, which track positions of a lot of objects, or stream databases, which process data streams from a lot of sensors, data Processed in such database systems are usually changed very rapidly and continuously. However, traditional database systems have a problem in processing these rapidly and continuously changing data because they suppose that a data item stored in the database remains constant until It is explicitly modified. The problem becomes more serious in the R-tree, which is a typical index structure for multidimensional data, because modifying data in the R-tree can generate cascading node splits or merges. To process frequent updates more efficiently, we propose a novel update technique for the R-tree, which we call the leaf-update technique. If a new value of a data item lies within the leaf MBR that the data item belongs, the leaf-update technique changes the leaf node only, not whole of the tree. Using this leaf-update manner and the leaf-access hash table for direct access to leaf nodes, the proposed technique can reduce update cost greatly. In addition, the leaf-update technique can be adopted in diverse variants of the R-tree and various applications that use the R-tree since it is based on the R-tree and it guarantees the correctness of the R-tree. In this paper, we prove the effectiveness of the leaf-update techniques theoretically and present experimental results that show that our technique outperforms traditional one.

Indexing Method for Constraint Moving Objects Using Road Connectivity (도로의 연결성을 이용한 제약적 이동 객체에 대한 색인 기법)

  • Bok, Kyoung-Soo;Yoon, Ho-Won;Seo, Dong-Min;Rho, Jin-Seok;Cho, Ki-Hyung;Yoo, Jae-Soo
    • The Journal of the Korea Contents Association
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    • v.7 no.7
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    • pp.1-10
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    • 2007
  • In this paper, we propose an indexing method for efficiently updating current positions of moving objects on road networks. The existing road network models increase update costs when objects move to adjacent road segments because their connectivity is not preserved. We propose an intersection based network model and a new index structure to solve this problem. The proposed intersection based network model preserves network connectivity through splitting road networks to contain intersection nodes always. The proposed index structure In our experiments, we show that our method is about 3 times faster than an existing index structure in terms of update costs.

Lazy Bulk Insertion Method of Moving Objects Using Index Structure Estimation (색인 구조 예측을 통한 이동체의 지연 다량 삽입 기법)

  • Kim, Jeong-Hyun;Park, Sun-Young;Jang, Hyong-Il;Kim, Ho-Suk;Bae, Hae-Young
    • Journal of Korea Spatial Information System Society
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    • v.7 no.3 s.15
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    • pp.55-65
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    • 2005
  • This paper presents a bulk insertion technique for efficiently inserting data items. Traditional moving object database focused on efficient query processing that happens mainly after index building. Traditional index structures rarely considered disk I/O overhead for index rebuilding by inserting data items. This paper, to solve this problem, describes a new bulk insertion technique which efficiently induces the current positions of moving objects and reduces update cost greatly. This technique uses buffering technique for bulk insertion in spatial index structures such as R-tree. To analyze split or merge node, we add a secondary index for information management on leaf node of primary index. And operations are classified to reduce unnecessary insertion and deletion. This technique decides processing order of moving objects, which minimize split and merge cost as a result of update operations. Experimental results show that this technique reduces insertion cost as compared with existing insertion techniques.

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A Group Update Technique based on a Buffer Node to Store a Vehicle Location Information (차량 위치 정보 저장을 위한 버퍼 노드 기반 그룹 갱신 기법)

  • Jung, Young-Jin;Ryu, Keun-Ho
    • Journal of KIISE:Databases
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    • v.33 no.1
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    • pp.1-11
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    • 2006
  • It is possible to track the moving vehicle as well as to develop the location based services actively according to the progress of wireless telecommunication and GPS, to the spread of network, and to the miniaturization of cellular phone. To provide these location based services, it is necessary for an index technique to store and search too much moving object data rapidly. However the existing indices require a lot of costs to insert the data because they store every position data into the index directly. To solve this problem in this paper, we propose a buffer node operation and design a GU-tree(Group Update tree). The proposed buffer node method reduces the input cost effectively since the operation stores the moving object location data in a group, the buffer node as the unit of a non-leaf node. hnd then we confirm the effect of the buffer node operation which reduces the insert cost and increase the search performance in a time slice query from the experiment to compare the operation with some existing indices. The proposed tufter node operation would be useful in the environment to update locations frequently such as a transportation vehicle management and a tour-guide system.

Spatio-Temporal Index Structure based on KDB-Tree for Tracking Positions of Moving Objects (이동 객체의 위치 추적을 위한 KDB-트리 기반의 시공간 색인구조)

  • Seo Dong-Min;Bok Kyoung-Soo;Yoo Jae Soo;Lee Byoung-Yup
    • Journal of Internet Computing and Services
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    • v.5 no.4
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    • pp.77-94
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    • 2004
  • Recently, the needs of index structure which manages moving objects efficiently have been increased because of the rapid development of location-based techniques. Existing index structures frequently need updates because moving objects change continuatively their positions. That caused entire performance loss of the index structures. In this paper, we propose a new index structure called the TPKDB-tree that is a spatio-temporal index structure based on KDB-tree. Our technique optimizes update costs and reduces a search time for moving objects and reduces unnecessary updates by expressing moving objects as linear functions. Thus, the TPKDB-tree efficiently supports the searches of future positions of moving objects by considering the changes of moving objects included in the node as time-parameter. To maximize space utilization, we propose the new update and split methods. Finally, we perform various experiments to show that our approach outperforms others.

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A Flash-based B+-Tree using Sibling-Leaf Blocks for Efficient Node Updates and Range Searches

  • Lim, Seong-Chae
    • International Journal of Internet, Broadcasting and Communication
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    • v.8 no.3
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    • pp.12-24
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    • 2016
  • Recently, as the price per bit is decreasing at a fast rate, flash memory is considered to be used as primary storage of large-scale database systems. Although flash memory shows off its high speeds of page reads, however, it has a problem of noticeable performance degradation in the presence of increasing update workloads. When updates are requested for pages with random page IDs, in particular, the shortcoming of flash tends to impair significantly the overall performance of a flash-based database system. Therefore, it is important to have a way to efficiently update the B+-tree, when it is stored in flash storage. This is because most of updates in the B+-tree arise at leaf nodes, whose page IDs are in random. In this light, we propose a new flash B+-tree that stores up-to-date versions of leaf nodes in sibling-leaf blocks (SLBs), while updating them. The use of SLBs improves the update performance of B-trees and provides the mechanism for fast key range searches. To verify the performance advantages of the proposed flash B+-tree, we developed a mathematical performance evaluation model that is suited for assessing B-tree operations. The performance comparisons from it show that the proposed flash B+-tree provides faster range searches and reduces more than 50% of update costs.

Update Cycle Detection Method of Control Limits using Control Chart Performance Evaluation Model (관리도 성능평가모형을 통한 관리한계선 갱신주기 탐지기법)

  • Kim, Jongwoo;Park, Cheong-Sool;Kim, Jun Seok;Kim, Sung-Shick;Baek, Jun-Geol
    • Journal of Korean Institute of Industrial Engineers
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    • v.40 no.1
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    • pp.43-51
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    • 2014
  • Statistical process control (SPC) is an important technique for monitoring and managing the manufacturing process. In spite of its easiness and effectiveness, some problematic sides of application exist such that the SPC techniques are hardly reflect the changes of the process conditions. Especially, update of control limits at the right time plays an important role in acquiring a reasonable performance of control charts. Therefore, we propose the control chart performance evaluation index (CPEI) based on count data model to monitor and manage the performance of control charts. The CPEI could indicate the degree of control chart performance and be helpful to detect the proper update cycle of control limits in real time. Experiments using real manufacturing data show that the proper update intervals are made by proposed method.

Enhanced Indexation Strategy with ETF and Black-Litterman Model (ETF와 블랙리터만 모형을 이용한 인핸스드 인덱스 전략)

  • Park, Gigyoung;Lee, Youngho;Seo, Jiwon
    • Korean Management Science Review
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    • v.30 no.3
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    • pp.1-16
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    • 2013
  • In this paper, we deal with an enhanced index fund strategy by implementing the exchange trade funds (ETFs) within the context of the Black-Litterman approach. The KOSPI200 index ETF is used to build risk-controlled portfolio that tracks the benchmark index, while the proposed Black-Litterman model mitigates estimation errors in incorporating both active investment views and equilibrium views. First, we construct a Black-Litterman model portfolio with the active market perspective based on the momentum strategy. Then, we update the portfolio with the KOSPI200 index ETF by using the equilibrium return ratio and weighted averages, while devising optimization modeling for improving the information ratio (IR) of the portfolio. Finally, we demonstrate the empirical viability of the proposed enhanced index strategies with KOSPI 200 data.

Embedded Node Cache Management for Hybrid Storage Systems (하이브리드 저장 시스템을 위한 내장형 노드 캐시 관리)

  • Byun, Si-Woo;Hur, Moon-Haeng;Roh, Chang-Bae
    • Proceedings of the KIEE Conference
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    • 2007.04a
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    • pp.157-159
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    • 2007
  • The conventional hard disk has been the dominant database storage system for over 25 years. Recently, hybrid systems which incorporate the advantages of flash memory into the conventional hard disks are considered to be the next dominant storage systems to support databases for desktops and server computers. Their features are satisfying the requirements like enhanced data I/O, energy consumption and reduced boot time, and they are sufficient to hybrid storage systems as major database storages. However, we need to improve traditional index node management schemes based on B-Tree due to the relatively slow characteristics of hard disk operations, as compared to flash memory. In order to achieve this goal, we propose a new index node management scheme called FNC-Tree. FNC-Tree-based index node management enhanced search and update performance by caching data objects in unused free area of flash leaf nodes to reduce slow hard disk I/Os in index access processes.

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A Consistency Control of Method for Spatial Data Cached in Mobile Clients (모바일 클라이언트에 캐쉬된 공간 데이터의 일관성 제어 기법)

  • 안경환;차지태;홍봉희
    • Journal of KIISE:Databases
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    • v.31 no.3
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    • pp.274-286
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    • 2004
  • In mobile client-server environments, mobile clients usually are disconnected with their server because of high cost of wireless communication and keep their own local copies to provide efficient updating the cached map. The update of the server database leads to invalidation of the cached map in the client side. To solve the issues of invalidation of the cached map, it is not efficient to resend part of the updated server database to clients whenever the updating of the server database occurs. This paper proposes a log-based update propagation method to propagate the server's update into its relevant clients by using only update logs. Too many logs increasingly accumulate as the sever database is updated several times. The sequential search of the relevant log data for a specific client is time-consuming. Sending of unnecessary logs should be avoided for reducing the overhead of communication.'re solve these problems, we first define unnecessary logs and then suggest log reduction methods to avoid or cancel creating unnecessary logs. The update log index is used for quickly retrieving relevant logs.