Conventional Database Systems Research Articles

大規模３次元文化財モデルを用いた関連情報検索表示および関連付けシステム

Recent advancements in digital archiving technologies have enabled us to store greater amounts of priceless digital data related to cultural properties. However, accessing this information by using conventional database systems is too difficult for general users. To solve this, this paper proposes an associating, retrieval and display system for archeological information using huge 3D models of cultural heritage as interfaces to access information. To define target regions on 3D models, users can quickly select specific regions from huge models by using an interface that combines a splitting method by graph-cut and a lasso tool. In the display process, we achieved highly interactive rendering of huge 3D models by using an efficient 3D rendering algorithm on the basis of multi-resolution meshes.

Online monitoring and visualisation of database structural deterioration

Structural deterioration of database is caused by updates of the database and can degrade performance seriously. Database reorganisation, which removes structural deterioration by relocating data in the secondary storage, is an administrator's headache; it is difficult to schedule reorganisation efficiently to keep acceptable performance because conventional database systems lack crucial monitoring facility of structural deterioration, with high resolution, high accuracy and low overhead. In order to make database reorganisation be easy for administrators and be autonomic in the future, the paper proposes an online database structure deterioration monitor, which can visualise structural deterioration distribution, with a novel structural deterioration model, a storage performance model and an incremental update technique. The experimental results with our prototype show that our scheme can monitor structural deterioration with an error of within 12% and with an overhead of 3% at most.

Development of SICA-COR, a food composition information system for Costa Rica

The Costa Rican Food Composition Information System (SICA-COR) has been developed to address the increased demands for local food information by health workers, decision makers, food industry, international commerce, and consumers. It has a software application that allows updating and managing of information in a more versatile, cost-effective and accessible way than conventional food composition database systems. The purpose of this work is to present the development and current state of SICA-COR. The system was developed using four main steps, identification of available food composition data, sources and needs; data capture and quality evaluation; development of the SICA-COR software; and establishment of the database. SICA-COR has a validated, LATINFOODS-compatible information capture form which includes detailed descriptions of the data sources, food names, and quality parameters and allows for inclusion of data for more than 80 nutritional components per 100 g edible food. The software was developed using a Microsoft ® SQL Server database engine and Java™. Of 1200 completed compilation forms, 83% fulfilled LATINFOODS standards and were incorporated into the database. Most of the data consists of values for energy, water, carbohydrate, fat, protein and ash. Pre-designed reports are available for specific and general end users such as members of the LATINFOODS Regional Center. The current SICA-COR Version (0.9) is a stand-alone application intended to eventually evolve to a web application. Specific actions to test and improve the software are underway.

An architecture for DICOM medical images storage and retrieval adopting distributed file systems

Conventional storage and retrieval of information from telemedicine environments is usually based on ordinary database systems. Aspects such as scalability, information distribution, high performance system techniques and operational costs are well known challenges to be circumvented in the research for novel proposals in the field of large-scale telemedicine systems. In this paper we present an architecture that targets high performance levels in storing and retrieving DICOM medical images, adopting a distributed approach in a cluster configuration. Our proposal has two main components: the first element is a data model that is based on image hierarchy, considering the hierarchical data format 5 (HDF5). The second component is a distributed file system, characterised by the parallel virtual file system (PVFS) that was employed in this proposal as a distributed storage data system. As a result, this paper presents a differentiated approach for storage and retrieval of information for a telemedicine environment. Experimental results, utilising the architecture, indicate an enhanced level of performance around 16% in terms of storage process. This number represents an improved performance in comparison to a conventional database system.

An XML-based methodology for parametric temporal database model implementation

Parametric data model is one of dimensional data models. It defines attributes as functions, modeling a real world object into a single tuple in a database. Such one-to-one correspondence between an object in the real world and a tuple provides various advantages in modeling dimensional data, avoiding self-joins which frequently appear in temporal data models which fragment an object into multiple tuples. Despite its modeling advantages, it is impractical to implement the parametric data model on top of conventional database systems because of the data model’s variable attribute sizes. However, such implementation challenge can be resolved by XML because XML is flexible for data boundaries. In this paper, we present an XML-based implementation methodology for the parametric temporal data model. In our implementation, we develop our own XML storage called CanStoreX (Canonical Storage for XML) and build the temporal database system on top of the CanStoreX.

Information overload and customization

IC systems are different from conventional search engines or database systems. IC systems are supposed to be the answer to information overload. They allow users to narrow what they are looking for and get information matching their needs. IC systems are also a bargain of consummate efficiency. The value proposition of such systems is reducing the time spent looking for information.

Adaptive Update Policy for Proactive Management of Deadline Miss Ratio and Data Freshness in Real-Time Database Models

Important applications, like e-commerce, online stock trading, traffic control demand real-time data services. Conventional database perform poor at these applications. A database for real-time data services has to support timing constraints and temporal consistency in addition to supporting characteristics of a conventional database system. In other words, it is desirable to execute transactions within its deadline using updated data reflecting the current world status. In order to achieve these objectives, the Quality of Service (QoS) metrics like miss ratio, data freshness, perceived freshness and Quality of Data (QoD) management schemes along with architectures for effective QoS management are introduced in Literature. These architectures accommodate the unpredictable change in user transactions and maintain QoS metrics by changing the update pattern of data items, which are periodically updated to reflect the real world status. In this study, we present architecture with an improved update policy and propose an algorithm to change the update pattern in such a manner that the system is able to maintain QoS metrics even under busty traffic conditions. The simulation results show that the proposed model can keep QoS metrics, like miss ratio and perceived freshness within limits under busty traffic conditions [1].

An efficient query optimization strategy for spatio-temporal queries in video databases

The interest for multimedia database management systems has grown rapidly due to the need for the storage of huge volumes of multimedia data in computer systems. An important building block of a multimedia database system is the query processor, and a query optimizer embedded to the query processor is needed to answer user queries efficiently. Query optimization problem has been widely studied for conventional database systems however it is a new research area for multimedia database systems. Due to the differences in query processing strategies, query optimization techniques used in multimedia database systems are different from those used in traditional databases. In this paper, a query optimization strategy is proposed for processing spatio-temporal queries in video database systems. The proposed strategy includes reordering algorithms to be applied on query execution tree. The performance results obtained by testing the reordering algorithms on different query sets are also presented.

An efficient query optimization strategy for spatio-temporal queries in video databases

The interest for multimedia database management systems has grown rapidly due to the need for the storage of huge volumes of multimedia data in computer systems. An important building block of a multimedia database system is the query processor, and a query optimizer embedded to the query processor is needed to answer user queries efficiently. Query optimization problem has been widely studied for conventional database systems; however it is a new research area for multimedia database systems. Due to the differences in query processing strategies, query optimization techniques used in multimedia database systems are different from those used in traditional databases. In this paper, a query optimization strategy is proposed for processing spatio-temporal queries in video database systems. The proposed strategy includes reordering algorithms to be applied on query execution tree. The performance results obtained by testing the reordering algorithms on different query sets are also presented.

Generic design of Web-based clinical databases.

BackgroundThe complexity and the rapid evolution and expansion of the domain of clinical information make development and maintenance of clinical databases difficult. Whenever new data types are introduced or existing types are modified in a conventional relational database system, the physical design of the database must be changed accordingly. For this reason, it is desirable that a clinical database be flexible and allow for modifications and for addition of new types of data without having to change the physical database schema. The ideal clinical database would therefore implement a highly-detailed logical database schema in a completely-generic physical schema that stores the wide variety of clinical data in a small and constant number of tables.ObjectiveThe objective was to review the medical literature regarding generic design of clinical databases.MethodsA search strategy was devised for PubMed and Google to get the best match of peer-reviewed articles and free Web resources on the subject.ResultsEight peer reviewed articles and a Web tutorial were found. All the resources described the so-called Entity-Attribute-Value (EAV) design as a means of simplifying the physical layout of data tables in a clinical database. In Entity-Attribute-Value design all data can be stored in a single generic table with conceptually 3 columns: 1 for entity (eg, patient identification), 1 for attribute (eg, name), and 1 for value (eg, "Jens Hansen"). To add more descriptive fields to the entity class, all that is necessary is to add attribute values to be stored in the attribute field. The main advantages of the Entity-Attribute-Value design are flexibility and effective entity-centered data retrieval. The main disadvantages are complicated front-end programming needed to display data in a conventional layout that the user understands and less-efficient attribute-centered queries. The Internet offers unique opportunities for database deployment, eliminating problems of user-interface deployment. Furthermore, Web forms may be generated in a completely-generic fashion during run time from metadata describing the semantic structure of clinical information stored in the database.ConclusionsThe Entity-Attribute-Value model is useful for generic design of clinical databases. Depending on the specific requirements of the application, more or less complex metadata models may be applied.

Realizing active data warehouses with off‐the‐shelf database technology

AbstractActive data warehouses belong to a new category of decision support systems, which automate decision making for routine decision tasks and semi‐routine decision tasks. Just as active database systems extend conventional database systems with event–condition–action rules for integrity constraint enforcement or procedure execution, active data warehouses extend conventional data warehouses with analysis rules that mimic the work of an analyst during decision making. This paper demonstrates how analysis rules can be implemented on top of a passive relational data warehouse system by using commercially available database technology. Copyright © 2002 John Wiley & Sons, Ltd.

Sunrise: A real-time event-processing system

Conceived at Bell Labs, Sunrise is a high-throughput, real-time event-processing and aggregation system. It offers many of the data-management features of a conventional database system, such as high-level, declarative programming interfaces and the traditional atomicity, consistency, isolation, and durability (ACID) correctness guarantees for transactions. Adapted to meet the needs of high-performance applications, Sunrise maintains its high throughput by using a shared-nothing parallel architecture that can deliver close to linear scale-up in practice. Sunrise achieves the real-time responsiveness (on the order of as little as a few milliseconds per transaction) that many emerging applications require by relying on the DataBlitz™ main-memory database system as its underlying single-site storage manager. The DataBlitz storage manager guarantees the fast access to correct data expected from a database system. The strength of Sunrise lies not only in its performance, but also in its flexibility. This paper introduces Sunrise and its two major components: a real-time analysis engine (RAE), at the heart of the runtime system, and a service authoring environment (SAE), which is the Sunrise authoring interface.

객체지향 데이터베이스 시스템에서 내포적 답의 처리 기법

기존 데이터베이스 시스템에서 질의를 처리할 때, 질의문의 응답은 사실이나 튜플들의 집합이다. 객체지향 데이터베이스 시스템에서도 객체들의 집합이 질의문의 응답이다. 그러나 추론적 데이터베이스 시스템에서는 질의문에 대하여 식의 집합으로 응답할 수 있으므로, 질의문 처리 비용을 절감할 수 있으며, 데이터베이스 상태와는 독립적인 좀 더 간결한 "내포적 답"으로 표현할 수 있다. 본 논문에서는 객체지향 데이터베이스 시스템에 규칙을 도입하여 추론적 데이터베이스 시스템에서 사용되는 내포적 질의문 처리 방법과 결합하여, 기존의 객체지향 데이터베이스 시스템에서 답을 얻을 수 없었던 불완전한 질의문에 대한 답을 얻을 수 있게 하였을 뿐만 아니라, 답의 클래스의 이름으로 표현함으로써, 답을 보다 명료하게 이해할 수 있게 해준다. When processing a query in a conventional database systems, a set of facts or tuples are usually returned as an answer. This also applies to object -oriented database where a set of objects is returned. Deductive database systems, however, provide the opportunity to obtain the answer of a query as a set of formulas, thereby reduce the costs to process the query, and represent its "intensional answers" in a more compact way independently of the database state. In this paper, by introducing rules info the object-oriented database systems and integrating the intensional query processing of deductive database systems into talc object-oriented database systems, we make it possible not only to answer incomplete queries which are not able to be answered in conventional object-oriented database systems, but also to express the answer-set abstractly as the names of classes, which provides us better understanding of the answer.

Shelter's donor datamart

AbstractThis paper discusses the issues and technical constraints that faced Shelter in their desire to extract intelligence from their donor database. Different options are discussed briefly, along with the rationale for deciding to develop an offline datamart. The paper also presents an explanation of the shortcomings of conventional relational database systems in relation to their use for data analysis, examines the difference between different types of offline data stores and explains the benefits achievable from the datamart solution. A description of Shelter's actual experience of designing, developing and using the datamart provides insights into the technical and other issues encountered, and demonstrates the effectiveness of the datamart as a fundraising tool. Copyright © 2001 Henry Stewart Publications

Real-time index concurrency control

Real time database systems are expected to rely heavily on indexes to speed up data access and thereby help more transactions meet their deadlines. Accordingly, high performance index concurrency control (ICC) protocols are required to prevent contention for the index from becoming a bottleneck. We develop real time variants of a representative set of classical B-tree ICC protocols and, using a detailed simulation model, compare their performance for real time transactions with firm deadlines. We also present and evaluate a real time ICC protocol called GUARD-link that augments the classical B-link protocol with a feedback based admission control mechanism. Both point and range queries, as well as the undos of the index action transactions are included in the study. The performance metrics used in evaluating the ICC protocols are the percentage of transactions that miss their deadlines and the fairness with respect to transaction type and size. Experimental results show that the performance characteristics of the real time version of an ICC protocol could be significantly different from the performance of the same protocol in a conventional (nonreal time) database system. In particular, B-link protocols, which are reputed to provide the best overall performance in conventional database systems, perform poorly under heavy real time loads. The new GUARD-link protocol, however, although based on the B-link approach, delivers the best performance (with respect to all performance metrics) for a variety of real time transaction workloads, by virtue of its admission control mechanism. GUARD-link provides close to ideal fairness in most environments.

MDARTS: a multiprocessor database architecture for hard real-time systems

Complex real time systems need databases to support concurrent data access and provide well defined interfaces between software modules. However, conventional database systems and prior real time database systems do not provide the performance or predictability needed by high speed, hard real time applications. The authors designed, implemented, and evaluated an object oriented database system called MDARTS (Multiprocessor Database Architecture for Real Time Systems). MDARTS avoids the client server overhead of most prior real time database systems and object oriented, real time systems by moving transaction execution into application tasks. By eliminating these sources of overhead and focusing on basic data management services for control systems (data sharing, serializable transactions, and multiprocessor support), the MDARTS prototype provides hard real time transaction times approximately three orders of magnitude faster than prior real time database systems. MDARTS ensures bounded locking delay by disabling preemption when a transaction is waiting for a lock, and hence, allows for the estimation of worst case transaction execution times. Another contribution of MDARTS is that it supports explicit declarations of real time requirements and semantic constraints within application code. The MDARTS library examines these declarations at application initialization time and attempts to construct objects that are compatible with the requirements. Besides local shared memory transactions with hard real time response time guarantees, MDARTS also supports remote transactions that use remote procedure calls for data access with less stringent timing constraints. The MDARTS prototype is implemented in C++ and it runs on VME based multiprocessors and Sun workstations.

Multifaceted object modeling with roles: A comprehensive approach

In conventional object-oriented database systems, it is assumed silently that fundamental object types and inter-object relationships can be classified statically, prescribing basic structural and behavioral properties for all the objects in the database. Such a classification-based approach falls short of supporting emerging data-intensive applications requiring more advanced dynamic capabilities. One of such advanced capabilities is the support of modeling subjectivity – the ability to (among others) provide multiple perspectives of application objects or to model so-called `multifaceted objects' which, on different stages, can exhibit different forms and behavior. This article describes an extended object-oriented approach that we have been investigating for this purpose. Advanced features embodied by dynamic and versatile role facilities have been introduced into a conventional object-oriented model, which facilitates specifying and modeling such applications in a natural, incremental and systematic way. Examples from automated manufacturing systems have been used to examine the necessity and utility of such advanced role facilities, and experimental prototype systems of the role mechanism have also been developed by exploiting different techniques and approaches of implementing roles.

ADVANCED CONCEPTUAL CLUSTERING AND ASSOCIATED QUERYING FACILITIES IN OBJECT-ORIENTED DATABASES

Conventional object-oriented database (OODB) systems follow a class-based approach to model real world entities and their relationships, which imposes several difficulties when more advanced "dynamic functions" are needed by the applications. One of such dynamic functions is conceptual clustering — the ability to dynamically group a set of existing objects together as a higher-level abstract object (called a "cluster"). The conceptual clustering model (CCM) that we have defined is an extension to current object-oriented models, which facilitates the modeling of dynamic, evolving, and/or ad hoc object clusters through a well-devised clustering mechanism that incorporates "roles". This paper presents the advanced features of CCM, along with its associated query language facilities devised for supporting general definition and access of clusters (and roles). An experimental prototype of the CCM has been constructed on top of a persistent object storage manager, running on a Sun4 workstation.

Active database systems

Active database systems support mechanisms that enable them to respond automatically to events that are taking place either inside or outside the database system itself. Considerable effort has been directed towards improving understanding of such systems in recent years, and many different proposals have been made and applications suggested. This high level of activity has not yielded a single agreed-upon standard approach to the integration of active functionality with conventional database systems, but has led to improved understanding of active behavior description languages, execution models, and architectures. This survey presents the fundamental characteristics of active database systems, describes a collection of representative systems within a common framework, considers the consequences for implementations of certain design decisions, and discusses tools for developing active applications.

A survey on content-based retrieval for multimedia databases

Conventional database systems are designed for managing textual and numerical data, and retrieving such data is often based on simple comparisons of text/numerical values. However, this simple method of retrieval is no longer adequate for multimedia data, since the digitized representation of images, video, or data itself does not convey the reality of these media items. In addition, composite data consisting of heterogeneous types of data also associates with the semantic content acquired by a user's recognition. Therefore, content-based retrieval for multimedia data is realized taking such intrinsic features of multimedia data into account. Implementation of the content-based retrieval facility is not based on a single fundamental, but is closely related to an underlying data model, a priori knowledge of the area of interest, and the scheme for representing queries. This paper surveys recent studies on content-based retrieval for multimedia databases from the point of view of three fundamental issues. Throughout the discussion, we assume databases that manage only nontextual/numerical data, such as image or video, are also in the category of multimedia databases.