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發(fā)器的操作包括 INSERT、DELETE 和 UPDATED.觸發(fā)器僅能在事件 INSERT、DELETE 和 UPDATE 之前觸發(fā),而不能在其后被觸發(fā)數(shù)據(jù)庫(kù)故障恢復(fù)技術(shù)所采用的主要策略是建立數(shù)據(jù)冗余,這些冗余數(shù)據(jù)包括(54) A.日常文檔、后備副本B.?dāng)?shù)據(jù)字典、日常文檔、后備副本C.后備副本和日志文件D.?dāng)?shù)據(jù)字典、日常文檔、后備副本和日志文件以下說(shuō)法中不正確的是(55)A.?dāng)?shù)據(jù)倉(cāng)庫(kù)是一個(gè)面向主題的、集成的、相對(duì)穩(wěn)定的、反映歷史變化的數(shù)據(jù)集合B.?dāng)?shù)據(jù)挖掘是從大量數(shù)據(jù)中挖掘出潛在的、有價(jià)值的知識(shí)的過(guò)程C.OLAP 和 OLTP 均以數(shù)據(jù)倉(cāng)庫(kù)為處理的基礎(chǔ)數(shù)據(jù)D.OLAP 面向數(shù)據(jù)操作人員,而 OLTP 一般面對(duì)決策管理人員實(shí)體聯(lián)系模型(簡(jiǎn)稱 ER 模型)的基本概念包括實(shí)體、屬性和聯(lián)系,其圖形表示稱為 ER圖。實(shí)體間聯(lián)系可以是(56)。ER 模型向關(guān)系模型轉(zhuǎn)換時(shí)就遵循以下原則:一個(gè)實(shí)體型轉(zhuǎn)換為一個(gè)關(guān)系模式,實(shí)體的屬性就轉(zhuǎn)換成關(guān)系的屬性,實(shí)體的碼就成為關(guān)系的碼;一個(gè)聯(lián)系型轉(zhuǎn)換為一個(gè)(57),與聯(lián)系相關(guān)聯(lián)的各實(shí)體的碼以及聯(lián)系的屬性轉(zhuǎn)換成(58)。一個(gè)多對(duì)多的聯(lián)系只能轉(zhuǎn)換成一個(gè)獨(dú)立的關(guān)系模式。在進(jìn)行轉(zhuǎn)換時(shí),與此聯(lián)系相連的各實(shí)體的碼以及聯(lián)系本身的屬性都轉(zhuǎn)換為關(guān)系的屬性,而關(guān)系的碼為(59)。(56) A.1:1 和 1:nC.1:n 和 m:n(57) A.聯(lián)系模式 C.?dāng)?shù)據(jù)模式 (58) A.聯(lián)系的屬性C.關(guān)系的碼 B.1:1 和 m:nD.1:1:n 和 m:nB.邏輯模式D.關(guān)系模式B.關(guān)系的屬性D.邏輯模式的屬性(59) A.任一實(shí)體的碼 B.各實(shí)體碼的組合C.任一實(shí)體的碼和聯(lián)系屬性組合 D.聯(lián)系的屬性CMM 提供了一個(gè)框架,將軟件過(guò)程改進(jìn)的進(jìn)化步驟組織成 5 個(gè)成熟度等級(jí)。除第 1 級(jí)外,每一級(jí)都包含了實(shí)現(xiàn)這一級(jí)目標(biāo)的若干關(guān)鍵過(guò)程域,每一個(gè)關(guān)鍵過(guò)程域又包含若干(60)。(60)A.關(guān)鍵實(shí)踐B.軟件過(guò)程性能C.軟件過(guò)程能力D.軟件過(guò)程(61)意味著一個(gè)操作在不同的類中可以有不同的實(shí)現(xiàn)方式。(61)A.多態(tài)性B.多繼承C.類的復(fù)用D.封裝軟件開(kāi)發(fā)的螺旋模型綜合了瀑布模型和演化模型的優(yōu)點(diǎn),并增加了(62)。采用螺旋模型時(shí),軟件開(kāi)發(fā)沿著螺線自內(nèi)向外旋轉(zhuǎn),每轉(zhuǎn)一圈都要對(duì)(63)進(jìn)行識(shí)別、分析,并采取相應(yīng)的對(duì)策。螺旋線第一圈的開(kāi)始點(diǎn)可能是一個(gè)(64)。從第二圈開(kāi)始,一個(gè)新產(chǎn)品開(kāi)發(fā)項(xiàng)目開(kāi)始了,新產(chǎn)品的演化沿著螺旋線進(jìn)行若干次迭代,一直運(yùn)轉(zhuǎn)到軟件生命期結(jié)束。(62)A.可行性分析(63)A.系統(tǒng)B.版本管理B.風(fēng)險(xiǎn) C.工程C.風(fēng)險(xiǎn)分析D.計(jì)劃D.項(xiàng)目管理(64)A.原型項(xiàng)目 B.概念項(xiàng)目C.改進(jìn)項(xiàng)目D.風(fēng)險(xiǎn)項(xiàng)目軟件測(cè)試計(jì)劃開(kāi)始于需求分析階段,完成于(65)階段。(65)A.需求分析 B.軟件設(shè)計(jì) C.軟件實(shí)現(xiàn)D.軟件測(cè)試 Basically,a firewall if a (66) process or a set of integrated processes that runs on a router or(67) to control the flow of networked application traffic(68) through it . Typically ,firewallsare placed on the entry point to a (69) network such as the Internet .They could be consideredtraffic cops. The firewall’s (70) is to ensure that all munication between an organization’snetwork and the internet conform to the organization’s security policies.(66) A.dependentC.related (67) A.browser C.repeater (68) A.pass C.passing (69) A.localC.private (70) A.mole C.role B.isolatedD.standaloneB.clientD.severB.passedD.passesB.nationalD.publicB.poleD.rule A Web browser is simply a terminal emulator, designed to display text on a screen. The two essential differences between an ordinary terminal emulator and a Web browser are that thebrowser knows how to deal with (71), and that it has a mechanism for (72) graphicalfiles. Display text ,display graphics , and (73) hyperlinks—there’s 99 percent of the (74)value. That’s not to say that the manufacturers didn’t go allout to attach a hyperactive efflorescence of useless capabilities onto their browsers. Remember when media channels in thebrowser were a big deal, instead of the clutter you can’t wait to delete from your favorites of