查詢結果分析
來源資料
頁籤選單縮合
| 題 名 | 一個分散式資料庫結構下的資料查詢及整合=The Database Query and Data Integration in Distributed Database Architecture |
|---|---|
| 作 者 | 呂芳懌; 趙尚威; | 書刊名 | 東海學報 |
| 卷 期 | 38:2(理學院) 民86.07 |
| 頁 次 | 頁55-68 |
| 分類號 | 312.49 |
| 關鍵詞 | 查詢解析; 資料整合; 資料字典; 分散式資料庫系統; Query decomposition; Data integration; Data dictionary; Distributed database system; |
| 語 文 | 中文(Chinese) |
| 中文摘要 | 在分散式資料庫中,資料的搜尋與合併是一個複雜而難解的問題。本文擬提出一 個可以解決這些問題的三層式( three-tier )分散式資料庫結構( Distributed Database Architecture, DDA )。 在 DDA 的結構中,為因應資料的分散性,使用者的要 求( request )必須分解成若干子要求( sub-requests ), 送往系統中各個工作站( site )處理, 各工作站執行後傳回的結果可能是完整的, 也可能是不完整的子表格( sub-table )。必須加以合併與整合之後才是所要的結果,文中將提出整合的方式。分解要 求及整合子表格時, 則必須根據資料字典( data dictionary )中所記錄之垂直條件與水 平條件。修正子要求及整合子表格的演算法與資料字典之結構一併於文中討論。 |
| 英文摘要 | Generally, query processing and data integration are two crucial problems in a distributed database environment. In this paper, we propose a three-tier distributed system architecture called Distributed Database Architecture (DDA) that is able to solve these two problems. When accepting a query Q from a user, DDA first divides Q into several subqueries, Qi, i=1,2,3,....n, and then analyzes and modifies the Qi's for adapting the non-centralized characteristics of data. After receiving the execution results, i.e., subtables, from the sites that execute Qi's, DDA tries to integrate these subtables to form the result of the original query. A data dictionary keeps the vertical and horizontal fragmentation information of a table. The divison of Q and the integration of the subtables are actually based on the content of the related data dictionaries. The algorithms for query division and data integration are also discussed in this article. |
本系統中英文摘要資訊取自各篇刊載內容。