物件導向資料庫內隱式查詢結果之研究

Abstract

傳統物件導向資料庫的查詢結果，均將符合查詢條件的物件一一列舉出來 ，這種對查詢結果的表示方法稱為外顯式表示法。這種表示法並未充份利 用物件導向資料模型中的語意成份，對資料庫使用者而言並不容易理解。 內隱式查詢結果則利用類別名稱與個別物件將符合查詢條件的物件表示出 來，因而彌補了以上的缺點。本文對於過去學者所提出的最佳化及聚合化 內隱表示法，就使用者認知 資料模型與實施架構三方面修改其缺點，提 出對應式內隱查詢結果。對應式內隱查詢結果以使用者所下達的查詢命令 為基礎，根據使用者所熟悉的概念找出其較容易理解的答案，以回應使用 者的查詢命令，因此使用者對於該查詢結果能夠理解的程度均能較最佳化 與聚合化查詢結果為佳。 The query results to conventional object-oriented data- base systems are the exhaustive enumeration of objects that satisfy the query predicates. Such expression is called explicit expression. Explicit expression does not take the advantage of the semantics in object-oriented data model and therefore the query answer is not much comprehensive for the users. Implicit query answers use class names and individual objects to express the query results and so make up for the explicit ones. This thesis modifies the research models of optimal and coherent implicit expressions that were proposed by previous researchers in user cognition, data model and implimentation architecture, and introduce the corresponding implicit query answer. Based on the query submitted by the user, the cor- responding implicit expression finds the query answer that is more comprehensive for the user according to the terms in the query that is farmiliar with the user. Therefore, the answer is more comprehensive than that of optimal and cohe- rent ones.