一個支援Web資料庫軟體維護之合作式環境

Abstract

Web 資料庫軟體的維護是一項困難且容易出錯的工作。這是由於很多設計時的決策是內嵌在file-based的Web資源上，並無法在執行期間直接得到。本論文討論如何設計一個以HED模型為基礎的合作式環境來支援Web資料庫軟體的維護。HED模型提供一個一般性的且牢固的基礎來維護Web資料庫軟體。此模型利用三種圖形─超鏈結圖、實體關係圖及資料流程圖─來表示Web資料庫軟體的程式邏輯。基於這個模型，受到某個修改所影響的程式可以透過結構性分析與資料庫分析而被準確的確認出來，並更進一步的提供維護上的支援。對於合作式環境方面，我們提供一致性控制、存取控制、及事件通知等功能來讓多人完成一項維護的工作。一致性控制、存取控制提供在共享資料上的協調操作。事件通知的功能則提供使用者知道其它使用者的各項活動，來達到分工合作的目的。

Maintenance of Web applications is a difficult and error-prone task because many design decisions are not directly accessible at run time, but rather embedded in file-based resources. This thesis discusses the issues for the design of a HED-based cooperative environment to support the maintenance of Web database applications. The HED model provides a general and solid foundation for maintaining Web database applications. The HED model is composed of three diagrams, hyperlink diagrams, entity-relationship diagrams, and data-flow diagrams, which are used to represent the logic of application programs. Based on HED model, the programs files affected by a program change can be identified precisely via the structure and database analyses. To deal with cooperation, we provide supports for concurrency control, access control, and event notification. The concurrency control and access control support cooperation on shared materials, and the notification mechanism supports cooperative works by maintaining awareness of each others' activity.