關(guān)于計算機(jī)的英語小短文
關(guān)于計算機(jī)的英語小短文
計算機(jī)出現(xiàn)于20世紀(jì)40年代,盡管其發(fā)展尚處于萌芽階段,但現(xiàn)在我們所熟悉的一些計算機(jī)詞匯在那時已開始產(chǎn)生,比如模擬和數(shù)碼,比特、數(shù)據(jù)和存儲器, 語言和程序,以及穿孔卡片和輸入。小編精心收集了關(guān)于計算機(jī)的英語小短文,供大家欣賞學(xué)習(xí)!
關(guān)于計算機(jī)的英語小短文篇一
DBMS的編排技巧
DBMS(Database Management System) 數(shù)據(jù)庫管理信息系統(tǒng)
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(shù)據(jù)項(xiàng)以回答用戶對信息的查詢,這就意味著DBMS能夠訪問和檢索非關(guān)鍵記錄字段的數(shù)據(jù),即DBMS能夠?qū)讉€大文件中邏輯相關(guān)的數(shù)據(jù)組織并連接在一起。
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(jié)構(gòu)。確定這些邏輯關(guān)系是數(shù)據(jù)管理者的任務(wù),由數(shù)據(jù)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(gòu)造技術(shù):
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.
2. 鏈表結(jié)構(gòu)。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(shù)據(jù)項(xiàng),它指出另一個邏輯相關(guān)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(biāo)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(fā)票文件以反映這些交易。
3. 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.
4. 這種情況下可使用鏈表結(jié)構(gòu),以顯示給定時間內(nèi)未支付的發(fā)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(fā)票文件(圖11-1)中該顧客的第一個發(fā)票的記錄位置,該發(fā)票記錄又依次與該顧客的下一個發(fā)票記錄相連,此鏈接的最后一個發(fā)票記錄由一個作為指針的特殊字符標(biāo)識。
關(guān)于計算機(jī)的英語小短文篇二
Oracle的數(shù)據(jù)庫管理功能
Oracle includes many features that make the database easier to manage. We've divided the discussion in this section into three categories: Oracle Enterprise Manager, add-on packs, backup and recovery.
Oracle Enterprise Manager
As part of every Database Server, Oracle provides the Oracle Enterprise Manager (EM), a database management tool framework with a graphical interface used to manage database users, instances, and features (such as replication) that can provide additional information about the Oracle environment.
Oracle包括許多使數(shù)據(jù)庫易于管理的功能,分三部分討論:Oracle企業(yè)管理者、附加包、備份和恢復(fù)。
Oracle企業(yè)管理者
Oracle數(shù)據(jù)庫服務(wù)器包括以下部分:Oracle企業(yè)管理者(EM)、一個帶有圖形接口的用于管理數(shù)據(jù)庫用戶、實(shí)例和提供Oracle環(huán)境等附加信息功能 (如:復(fù)制) 的數(shù)據(jù)庫管理工具框架。
關(guān)于計算機(jī)的英語小短文篇三
E-mail地址中的符號@是什么意思
That little "a" with a circle curling around it that is found in email addresses is most commonly referred to as the "at" symbol.
小寫字母a外加個圓圈,這一符號常出現(xiàn)在email(電子郵件)地址中,通常是作為"at"(在)的標(biāo)記。
Surprisingly though, there is no official, universal name for this sign. There are dozens of strange terms to describe the @ symbol.
然而令人感到驚奇的是,這一標(biāo)記居然沒有官方的,通用的名稱。有幾十個奇怪的術(shù)語用來描繪@這一符號。
Before it became the standard symbol for electronic mail, the @ symbol was used to represent the cost or weight of something. For instance, if you purchased 6 apples, you might write it as 6 apples @ class="main">
關(guān)于計算機(jī)的英語小短文
關(guān)于計算機(jī)的英語小短文
With the introduction of e-mail came the popularity of the @ symbol. The @ symbol or the "at sign" separates a person's online user name from his mail server address. For instance, joe@uselessknowledge.com. Its widespread use on the Internet made it necessary to put this symbol on keyboards in other countries that have never seen or used the symbol before. As a result, there is really no official name for this symbol.
隨著電子郵件的使用,@這一符號越來越普及了。符號@或'at'標(biāo)記將上網(wǎng)用戶的姓名與其郵件的服務(wù)器地址分開。例如:joe@uselessknowledge.com。 這一符號在因特網(wǎng)上的廣泛使用使得許多以前從未見過或使用過它的國家必須在它們的電腦鍵盤上加上這一符號鍵,結(jié)果造成這一符號并沒有真正的官方名稱。
The actual origin of the @ symbol remains an enigma.
@符號的確切起源仍然是謎。
History tells us that the @ symbol stemmed from the tired hands of the medieval monks. During the Middle Ages before the invention of printing presses, every letter of a word had to be painstakingly transcribed by hand for each copy of a published book. The monks that performed these long, tedious copying duties looked for ways to reduce the number of individual strokes per word for common words. Although the word "at" is quite short to begin with, it was a common enough word in texts and documents that medieval monks thought it would be quicker and easier to shorten the word "at" even more. As a result, the monks looped the "t" around the "a" and created it into a circle-eliminating two strokes of the pen.
歷史告訴我們,@這一符號起源于中世紀(jì)僧侶疲勞的雙手。中世紀(jì)時印刷機(jī)尚未發(fā)明,要出版一本書,每一個單詞的每一個字母都得用手工辛苦的刻出來。從事這項(xiàng)長時間辛苦謄寫刻畫的僧侶們就開始尋找減少每一個常用字筆畫數(shù)的方法。雖然"at"這一單詞開始寫起來很短,但它在文本和文件中頻繁出現(xiàn)。中世紀(jì)的僧侶們就想到如果能進(jìn)一步簡化它,就可以寫起來更快更容易。結(jié)果,僧侶們就在a四周畫了一個圈,從而省卻了字母"t"的兩個筆劃。
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