物件永續化是應用系統設計時經常會面臨的需求，傳統做法是由開發人員自行設法將物件轉為資料庫可接受的格式，再存入後端資料庫。但這往往使得開發人員必須同時處理兩種資料模型，除了應用系統所用的物件模型之外，開發人員還要處理後端資料庫所用的資料模型，譬如表格等，以及兩種模型間的轉換。這不僅增加系統開發的複雜度，維護系統亦不容易。新的資料永續性技術Java資料物件（JDO）提供一個標準的框架，能夠幫助開發人員代為處理物件永續化的問題。因此開發人員能夠以單純的物件模型發展應用系統。另一方面，XML技術的興起帶動XML文件在資料交換與儲存方面的加速發展，其中專門儲存XML文件的資料庫也日益普遍。我們的研究是在瞭解如何使用XML資料庫為後端的資料儲存庫，而對Java物件進行物件永續化。 / Object persistence often comes up at the development of the application systems. Traditionally, the developers should try to transfer the objects to forms that databases can accept, and then store them in databases. But this often makes developers deal with two kinds of data models at the same time: besides object model that the application usually uses, the developers should also deal with the data model used for the backend database, like the relation model, and the conversion between both models. This not only increases the complexity of the system, but also the difficulty to maintain the system. A new technology of object persistence is Java Data Objects (JDO), which offer a standard framework to help developers to deal with object persistence so that the developers can concern themselves with object model only. On the other hand, the rise of XML technologies makes it attractive in data exchange and storage. The use of XML databases as data repositories becomes more and more common. Our research in the thesis is to realize JDO by serializing Java objects as XML documents and use XML databases as persistent repositories to store the resulting documents.

XML (eXtensible Markup Language)是今日新興在網路上所使用的延伸性的標記語言。它具有豐富的語意表達及與展現方式獨立的資料獨立性。由於這些特性，使得XML成為新的資料交換標準並且其應用在資料庫中產生了許多新的研究議題在資料儲存和查詢處理上。在本篇研究中，將研究XML資料庫中的績效評估的議題並且發展一個可適用於不同應用領域及各種平台上的使用者導向且開放型工作量模式以評估XML資料庫績效。此XML開放型的工作量模型包含三個子模型─XML資料模型、查詢模型以及控制模型。XML資料模型將模式化XML文件中階層式的結構概念；查詢模型包含了一連串查詢模組以供測試XML資料庫的處理查詢能力以及一個開放型的查詢輸入介面以供使用者依照需求設定所需的測試查詢；控制模型中定義了一連串變數以供設定績效評估系統中的執行環境。我們發展此系統化且具開放型的工作量方法可以幫助各種不同應用領域的使用者預測及展現XML資料庫系統的績效。 / XML (eXtensible Markup Language) is the emerging data format for data processing on the Internet. XML provides a rich data semantics and data independence from the presentation. Thanks to these features, XML becomes a new data exchange standard and leads new storage and query processing issues on database research communities. In this paper, the performance evaluation issues on XML databases have been studied and a generic and requirement-driven XML workload model that is applicable to any application scenario or movable on various platforms is developed. There are three sub-models in this generic workload model, the XML data model, the query model, and the control model. The XML data model formulates the generic hierarchy structure of XML documents and supports a flexible document structure of the test database. The XML query model contains a flexible classical query module selector and an open query input to define the requirement-driven test query model to challenge the XML query processing ability of the XML database. The control model defines variables that are used to set up the implementation of a benchmark. This open, flexible, and systematic workload method permits users in various application domains to predicate or profile the performance of the XML database systems.