近年來，隨著計算機技術的飛速發展，越來越多的行業都會涉及到互聯網業務。由於業務量的不斷增多，資料總量不斷變大，傳統的集中式資料庫逐漸無法滿足資料存儲的需求。與傳統集中式資料庫不同，分佈式資料庫(Distributed Database)具有更高的靈活性，更高的可用性、可靠性，並且在海量資料的需求下，具有明顯的成本優勢，和更高的效率。本文以網路購物系統為例，設計和實現了一個分佈式資料庫系統。
本系統使用MVC設計模式，對請求進行接收與回執，使用網頁瀏覽器作為前端交互界面，實作了一個核心業務(Core Service)處理元件(Component)，對接收到的請求作處理分發，以多個MySQL關係型資料庫作為子節點(Node)，實現對資料的存取。
本系統具有維持用戶登錄，記錄用戶信息，瀏覽并購買商品，并對經營者提供一個后臺管理系統，對商品信息與庫存進行維護，與系統狀態的監測等功能。經測試，該系統能夠在服務器上運行良好並可以實現分佈式事務功能，比集中式資料庫具備更高的效率、擴展性與可靠性。

In recent years, Internet business has been permeated into almost all industries as computer technology advances. Since the huge increment in business volume and total data, traditional centralized database can no longer satisfy the need for data storage. Compared with traditional centralized database, distributed database has the attributes of more flexibility, availability and reliability. Especially, under the condition of processing massive data, distributed database can perform more efficiently with lower costs. In this thesis, a distributed database has been designed and implemented by the case of on-line shopping system.
The on-line shopping system is framed by the MVC design pattern, which is able to send and receive requests from users. Users would interactive with this system through the net browser. A component called "CoreService" is achieved to distribute all the received requests. Data, storing in several MySQL databases, can be got and stored by nodes.
System can keep login status, record user-information and monitor system status. Customers can browse and buy products. On the other hand, managers can maintain product information and inventory by the background management system. The system can be well executed on a service and implements the function of distributed transaction. Compared with centralized database, this system has been confirmed to perform better on web service with more effectiveness, flexibility and reliability.

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