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A Bitemporal SQL Database Design Method from the Enhanced Entity-Relationship Model
(2021-04-01)
Chau, Vo Thi Ngoc
;
Chittayasothorn, Suphamit
Recently temporal supports have been included in the SQL standards, leading to a great bridge between research works and real-world applications. However, showing this bridge in practice needs to be considered more. Such a shortage needs to be resolved due to the fact that time is ubiquitous in every application domain. In this paper, we propose a novel design method to design a bitemporal SQL database from an enhanced-entity-relationship schema. From this conceptual schema, a bitemporal SQL database schema is defined automatically. As a theoretical evaluation, our proposed method is novel in the following points. Firstly, although the method is dedicated to bitemporal databases, its starting point is with the enhanced entity-relationship model which is so popular that practicing database designers can work with it well. Secondly, its temporal supports are explicitly extracted and included in the data model mapping in an automatic manner. The automatic mapping process is based on topological sorting and thus performed in a certain sequence to derive a bitemporal SQL database schema with the SQL temporal support. Above all, our method helps easily deploy bitemporal databases in real-world applications. Indeed, its illustration has been shown comprehensively for VNUMED, an intermediate research medical database.
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A conceptual schema-based temporal meta database schemas generation technique for 3D objects
(2010-01-01)
Chau, Vo Thi Ngoc
;
Chittayasothorn, Suphamit
In this paper, a temporal meta database for three-dimensional (3D) objects whose properties and relationships are supported by valid time is introduced. Based on our proposed temporal object-oriented conceptual schema model, a conceptual schema of the temporal meta database can be generated from a 3D graphical data source and other particular application requirements. Based on our proposed temporal object relational data model with attribute timestamping, logical schemas of the temporal meta database can be systematically and automatically generated from the conceptual schema. From the temporal meta database, non-temporal/temporal metadata about temporal 3D objects are available for temporal information system users. Convenient access using database languages such as SQL can be performed. Queries over 3D objects using a temporal object relational SQL are demonstrated. © 2009 Springer-Verlag London Limited.
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Temporal 3D graphical data management from a database perspective
(2009-11-16)
Chau, Vo Thi Ngoc
;
Chittayasothorn, Suphamit
According to recent advances in computer science and engineering, three dimensional (3D) graphical data is of growing interest in many application areas. In this paper, a data management technique is proposed to handle 3D graphical data with the time dimension from a database perspective. Different from the existing works, our technique deals with 3D graphical data in all of the three various aspects: the visual aspect for the 3D graphical data part, the semantic aspect for the metadata part, and especially the temporal aspect for changes over the time. As a result, 3D graphical data can be managed properly with semantics and time. Therefore, many front-end applications can conveniently have access to them at both graphical and semantic data levels for sharability and reusability. © 2009 IEEE.
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A temporal object relational SQL language with attribute timestamping in a temporal transparency environment
(2008-12-01)
Chau, Vo Thi Ngoc
;
Chittayasothorn, Suphamit
In this paper, a temporal object relational SQL language is proposed. It is intended to facilitate the non-procedural data definitions, queries, and modifications of temporal databases with attribute timestamping in a temporal transparency environment. With attribute timestamping, temporal data of any type is naturally handled. With temporal logic, users can issue temporal queries in an intuitively expressive manner. The language provides valid time support for upward compatibility, temporal upward compatibility, sequenced and non-sequenced variants to serve both non-temporal and temporal users. Using object relational technology, the implementation is made for embedded and interactive SQL modes. All existing interfaces of an ORDBMS are inherited with temporal transparency. © 2008 Elsevier B.V. All rights reserved.
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A temporal meta database system for 3D objects
(2007-12-01)
Chau, Vo Thi Ngoc
;
Chittayasothorn, Suphamit
Nowadays, semantic information accompanying 3D graphical data, which is called metadata, has been realized to be essential for several purposes such that available 3D graphical data can be indexed and retrieved by means of its metadata and then other applications can make use of the 3D graphical data efficiently. Even though a number of works have focused on this topic so far, no temporal aspect of 3D graphical data has been taken into account. Especially no complete automatic metadata extraction process has been proposed. A manual process is possible with a small amount of 3D graphical data while impossible with a larger amount. Therefore, the manual process gets heavy and the cost in time and effort is so much required. In such a context, we introduce for 3D graphical data a temporal meta database system where an automatic metadata extraction method takes into consideration the temporal aspect of 3D graphical data. 3D graphical data is arranged in a scene formatted in the standard language VRML. Semantic information of the scene, i.e. metadata, will be automatically achieved. The structure of scene metadata is handled by using the temporal NIAM object oriented conceptual schema model at the abstraction level so that the semantic scene information can get more understandable to users, graphics designers, and application programmers as well. As a result, scene metadata is able to be easily stored and queried by means of some standardized database language such as SQL or OQL. With the aid of the extracted scene metadata, the respective 3D scenes are now exactly and conveniently accessed by other applications such as a virtual guide in transportation, architecture, tourism, etc. © 2007 IEEE.
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The design and implementation of an ORM-based information warehouse
(2005-12-01)
Chau, Vo Thi Ngoc
;
Chittayasothorn, Suphamit
Since 1995, star schema has been popularly utilized to represent warehouse data at the logical level. Information warehouse design mainly focuses on the design of a warehouse star schema. There are many proposals on conceptual data warehouse design of a star schema based on some well-known data models such as the Entity Relationship Model (ERM), and an extension to the Unified Modeling Language (UML). This paper presents the design and implementation of an information warehouse using the Object Role Model (ORM) as the data model both for user modeling of the warehouse and for the underlying implementation model of the system. A warehouse multi-star/star schema is automatically generated from the input schema description based on ORM using a deep-structured natural language interface. Users input simple English sentences together with the structured sections for type declarations and constraints on these sentences. Since the input ORM schema can also be transformed into 5NF operational relational schemas, this system allows warehouse users to generate star schemas from their operational schemas.

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