講述計算機DBMS的編排技巧的英語
英語和計算機是對於我們的生活都很經常用的東西了，所以小編今天就給大家整理了有關於計算機的英語，大家要閱讀一下哦
sequential 順序的，連續的
integrate 綜合，使成整體
access v. 訪問
retrieve v.找回，檢索
employ v.使用
list structure n.鏈表結構
invoice n. 發票
pointer n.指針
hierarchical structure 樹結構
subordinate adj. 從屬的
network structure 網狀結構
relational structure 關係結構
physical structure 物理結構
Abbreviations:
DBMS(Database Management System) 數據庫管理信息系統
DBMS is able to access and retrieve data from nonkey record fields. That is, the DBMS is able to structure and tie together the logically related data from several large files.
DBMS可綜合幾個文件的數據項以回答用戶對信息的查詢，這就意味着DBMS能夠訪問和檢索非關鍵記錄字段的數據，即DBMS能夠將幾個大文件中邏輯相關的數據組織並連接在一起。
Logical Structures. Identifying these logical relationships is a job of the data administrator. A data definition language is used for this purpose. The DBMS may then employ one of the following logical structuring techniques during storage access, and retrieval operations [1]:
邏輯結構。確定這些邏輯關係是數據管理者的任務，由數據定義語言完成。DBMS在存儲、訪問和檢索操作過程中可選用以下邏輯構造技術:
1. List structures. In this logical approach, records are linked together by the use of pointers. A pointer is a data item in one record that identifies the storage location of another logically related record. Records in a customer master file, for example, will contain the name and address of each customer, and each record in this file is identified by an account number. During an accounting period, a customer may buy a number of items on different days. Thus, the company may maintain an invoice file to reflect these transactions.
鏈表結構。在該邏輯方式中，記錄通過指針鏈接在一起。指針是記錄中的一個數據項，它指出另一個邏輯相關的記錄的存儲位置，例如，顧客主文件中的記錄將包含每個顧客的姓名和地址，而且該文件中的每個記錄都由一個賬號標識。在記賬期間，顧客可在不同時間購買許多東西,公司保存一個發票文件以反映這些交易。
A list structure could be used in this situation to show the unpaid invoices at any given time. Each record in the customer file would contain a field that would point to the record location of the first invoice for that customer in the invoice file (fig11-1). This invoice record, in turn, would be linked to later invoices for the customer. The last invoice in the chain would be identified by the use of a special character as a pointer.
這種情況下可使用鏈表結構，以顯示給定時間內未支付的發票。顧客文件中的每個記錄都包含這樣一個字段，該字段指向發票文件(圖11-1)中該顧客的第一個發票的記錄位置，該發票記錄又依次與該顧客的下一個發票記錄相連，此鏈接的最後一個發票記錄由一個作爲指針的特殊字符標識。
