數(shù)據(jù)庫(kù)選擇判斷題(中英文)

1、1. A primary key is a field (or group of fields) that uniquely describes each record in the database. T2. Data redundancy improves the integrity of a database. 3. SQL is the language used by relational databases to create objects and to manipulate and retrieve data.4. A relational database managemen

2、t system does not include tools for backing up & restoring databases. 5. 1，一種主鍵是一個(gè)字段（或字段組）唯一地描述了每個(gè)記錄在數(shù)據(jù)庫(kù)中。6. 2.數(shù)據(jù)冗余改善了數(shù)據(jù)庫(kù)的完整性。7. 3，SQL是關(guān)系型數(shù)據(jù)庫(kù)用于創(chuàng)建對(duì)象，并以操作和檢索數(shù)據(jù)的語(yǔ)言。8. 4.關(guān)系數(shù)據(jù)庫(kù)管理系統(tǒng)并不包括用于備份和恢復(fù)數(shù)據(jù)庫(kù)的工具。9. An attribute is also known as a row in most databases. 10. An association between entities is known

3、as a relationship. 11. Integrity constraints limit the number of entities that can be placed in a table or database. 12. The Entity-Relationship data model is often used in the physical design phase.13. The concept “relation” in relation model is exactly the same as the concept “relationship” in ER

4、model.14. 9.一種屬性也被稱為一個(gè)行中大多數(shù)數(shù)據(jù)庫(kù)。15. 10.實(shí)體之間的關(guān)聯(lián)稱為關(guān)系。16. 11.完整性約束限制可以被放置在一個(gè)表或數(shù)據(jù)庫(kù)實(shí)體的數(shù)目。17. 12.實(shí)體關(guān)系數(shù)據(jù)模型中經(jīng)常使用的物理設(shè)計(jì)階段。18. 13.在關(guān)系模型的概念'關(guān)系'是完全一樣的ER模型的概念的“關(guān)系”。19. Most relationship sets in a database system involves two entity sets.20. The closure of an attribute set contains that attribute set.21. Lo

5、ssless decomposition is necessary in a decomposition algorithm.22. If A B and C D hold, then AC BD also holds.23. It is not necessary that a legal schedule preserves the order in which the instructions appear in each individual transaction.24. Update operations in database must be written into log b

6、efore updating database.25. 19.大多數(shù)關(guān)系套在數(shù)據(jù)庫(kù)系統(tǒng)中包括兩個(gè)實(shí)體集。26. 設(shè)置屬性20.關(guān)閉包含的屬性設(shè)置。27. 21.無(wú)損分解是必要的分解算法。28. 22.如果AB和Cd握住，然后ACBD還持有。29. 23.這是沒(méi)有必要，一個(gè)法律時(shí)間表保留在其中的指令出現(xiàn)在每個(gè)單獨(dú)的事務(wù)處理的次序。30. 在數(shù)據(jù)庫(kù)24的更新操作必須寫入日志更新數(shù)據(jù)庫(kù)之前。未知答案：1. At its simplest, a database can be seen as a collection of related data. 2. If a salesperson attem

7、pts to order merchandise for a customer not in the customer service database, the database will typically generate an error message. This message indicates that an integrity constraint has been violated. 3. An advantage of using a relational database is to facilitate consistency. 4. With the six bas

8、ic operations (union, difference, selection, projection, product, and renaming), relational algebra is complete. Other operations are just syntactic sugar and can be derived from the basic operations.5. Once a transition is committed, the changes it has made to database persist across system crashes

9、, that is, consistency.6. 1.在其最簡(jiǎn)單的，數(shù)據(jù)庫(kù)可以被看作是相關(guān)的數(shù)據(jù)的集合。7. 2.如果營(yíng)業(yè)員試圖訂購(gòu)商品的顧客不是在客戶服務(wù)數(shù)據(jù)庫(kù)，該數(shù)據(jù)庫(kù)將典型地產(chǎn)生一個(gè)錯(cuò)誤信息。此消息表明完整性約束已經(jīng)被破壞。8. 3.使用關(guān)系數(shù)據(jù)庫(kù)的一個(gè)優(yōu)點(diǎn)是便于一致性。9. 4.在六種基本操作（集，差，選擇，投影，產(chǎn)品和重命名），關(guān)系代數(shù)完成。其他的操作都只是語(yǔ)法糖，并且可以從基本操作得到的。10. 5.一旦過(guò)渡被提交，已作出的數(shù)據(jù)庫(kù)中的改變持續(xù)整個(gè)系統(tǒng)崩潰，即，一致性。1. _ is the most widely used data model A. relational mod

10、el B. entity-relationship modelC. object-based data model D. semi-structured data model 是最廣泛使用的數(shù)據(jù)模型A.關(guān)系模型B.實(shí)體關(guān)系模型C.基于對(duì)象的模型數(shù)據(jù)D.半結(jié)構(gòu)化的數(shù)據(jù)模型一個(gè)關(guān)系模式是一組_。A.元組B.屬性C.列D.行2. A relation schema is a set of _.A. tuples B. attributes C. columns D. rows3.一組屬性，這些屬性，采取集體，使我們能夠唯一標(biāo)識(shí)關(guān)系中的一個(gè)元組被稱為_的。A.超鍵B.主鍵C.候選鍵D.外鍵3. A s

11、et of attributes that, taken collectively, allow us to identify uniquely a tuple in the relation is called _.A. super key B. primary key C. candidate key D. foreign key4.應(yīng)用程序用戶在_級(jí)數(shù)據(jù)交互。A.物理B.邏輯C.查看D.以上所有的4. Application users interact with data in the _ level.A. physical B. logical C. view D. all of t

12、he above5.關(guān)系代數(shù)是_語(yǔ)言A.程序B.聲明C.自然D.商業(yè)5. Relational algebra is a _ languageA. procedural B. declarative C. natural D. commercial6.關(guān)系代數(shù)的基本操作包括_。A.廣義投影，聚合函數(shù)，外部聯(lián)接B.設(shè)置交集，自然連接，分立，轉(zhuǎn)讓C.選擇，項(xiàng)目設(shè)置工會(huì)，設(shè)置不同，笛卡爾積，重命名D.設(shè)置路口，設(shè)置工會(huì)，設(shè)置不同的6. The fundamental operations of relational algebra includes_.A. generalized projectio

13、n, aggregate function, outer joinB. set-intersection, natural join, division, assignmentC. select, project, set-union, set-difference, Cartesian product, renameD. set-intersection, set-union, set-difference7.如果表S有M列，表T具有N列，那么S和T的笛卡爾積具有_列。A.M。* N B. M-N C. M + N D. M + N-17. If table S has M columns,

14、 table T has N columns, then the Cartesian product of S and T has _ columns.A. M*N B. M-N C. M+N D. M+N-18.關(guān)系代數(shù)的_操作需要兩個(gè)參與關(guān)系有屬性的數(shù)相同。A.師B.參加C.笛卡爾積D.單位8. The _ operation in relational algebra requires the two participating relations have the same number of attributes.A. division B. join C. Cartesian pr

15、oduct D. union9. _不包含在SQL語(yǔ)言？A.查詢?cè)u(píng)估B.完整性C.查看D.授權(quán)9. _is not contained in SQL language? A. query evaluation B. integrity C. view D. authorization10. 在SQL語(yǔ)句選擇關(guān)鍵字對(duì)應(yīng)關(guān)系代數(shù)的_操作。A.選擇B.投影C.參與D.鴻溝10. The SELECT keyword in a SQL statement corresponds to the _ operation in relational algebra.A. select B. projecti

16、on C. join D. divide 11. SQL語(yǔ)言用_語(yǔ)句從數(shù)據(jù)庫(kù)中刪除表。A.廢除B.刪除C.卸下D. DROP11. SQL language use the _ statement to remove a table from database.A. REVOKE B. DELETE C. REMOVE D. DROP 12.使用視圖是_有益的。A.并發(fā)控制B.安全C.故障恢復(fù)D.以上所有的12. Using views is beneficial to _.A. concurrency control B. security C. failure recovery D. al

17、l of the above13.觸發(fā)器可以定義一些要執(zhí)行的動(dòng)作_在數(shù)據(jù)庫(kù)中的一些事件。A.C。，代替D.后B之前所有上述13. A trigger can define some actions to be executed _ some events in database.A. before B. after C. instead of D. all of the above14. _不是ER模型的基本概念。A.實(shí)體B.關(guān)系C.程度D.屬性S的14. _ is not the basic notions of the E-R model.A. entity B. relationship

18、 C. degree D. attribute15.如果映射基數(shù)從實(shí)體集合S到實(shí)體集T是一對(duì)多，則T的實(shí)體與_實(shí)體相關(guān)聯(lián)（實(shí)體）答：一個(gè)B.最多一個(gè)C.至少一個(gè)D.多15. If the mapping cardinality from entity set S to entity set T is one to many, then an entity of T is associated with _ entity(entities) of S.A. one B. at most one C. at least one D. many16.一種通過(guò)該關(guān)系被視為更高級(jí)別的抽象實(shí)體被稱為_。A

19、.聚集B.泛化C.專業(yè)化D.屬性繼承16. An abstraction through which relationships are treated as higher-level entities is called _.A. aggregation B. generalization C. specialization D. attribute inheritance17.映射ER圖到關(guān)系模式可以在該階段發(fā)生_。A.需求分析B.概念設(shè)計(jì)C.邏輯設(shè)計(jì)D.物理設(shè)計(jì)17. Mapping an E-R diagram into relation schemas can happen in t

20、he phase of _.A. requirement analysis B. conceptual design C. logical design D. physical design18. _關(guān)系組表示為與兩個(gè)參與實(shí)體集的主鍵屬性的模式。A.一到1 B.一到多C.許多對(duì)一D.多對(duì)許多18. A _ relationship set is represented as a schema with attributes for the primary keys of the two participating entity sets.A. one-to-one B. one-to-many

21、 C. many-to-one D. many-to-many19.從函數(shù)依賴集F = AB，BCD，Cê，我們可以推斷that_。A.交流ABCDE B. BCABCDE C. CDABCDE D.以上都不是19. From the functional dependency set F=AB, BCD, CE, we can infer that_.A. ACABCDE B. BCABCDE C. CDABCDE D. none of the above20. _消除了可以基于函數(shù)依賴發(fā)現(xiàn)的所有冗余A. 1NF B. 2NF C. 3NF D. BCNF20. _ elimina

22、tes all redundancy that can be discovered based on functional dependenciesA. 1NF B. 2NF C. 3NF D. BCNF21.我們必須確保_在數(shù)據(jù)庫(kù)設(shè)計(jì)的性能。A. BCNF B.無(wú)損分解C.依賴保鮮D. 3NF21. We must ensure the property of _ in database design.A. BCNF B. lossless decomposition C. dependency preservation D. 3NF22. _不是事務(wù)的屬性A.積極B.一致性C.隔離D.耐久

23、性22. _is not the property of transactions.A. active B. consistency C. isolation D. durability23. _控制并發(fā)事務(wù)中的交互。答：查詢處理器B.存儲(chǔ)管理器C.并發(fā)控制管理器D.數(shù)據(jù)庫(kù)管理員23. _ controls interactions among concurrent transactions.A. query processor B. storage managerC. concurrency control manager D. database administrator24. _of以下

24、指令對(duì)不沖突。A.閱讀（Q），閱讀（Q）B.閱讀（Q），寫（Q）C.寫（Q），閱讀（Q）D.寫（Q），寫（Q）24. _of the following pairs of instructions do not conflict.A. read(Q), read(Q) B. read(Q), write(Q) C. write(Q), read(Q) D. write(Q), write(Q)25.可序列化調(diào)度相當(dāng)于_串行調(diào)度（S）。A.只有一個(gè)B.至少一個(gè)C.至多一個(gè)D.任何數(shù)量的25. A serializable schedule is equivalent to _ serial sc

25、hedule(s).A. only one B. at least one C. at most one D. any number of26.如果一個(gè)事務(wù)T已經(jīng)在數(shù)據(jù)項(xiàng)Q上獲得共享鎖，則T可以_ Q.A.讀取B.寫C.讀寫D.既不會(huì)讀也不會(huì)寫交易的S26. If a transaction T has obtain a shared lock on data item Q, then T can _ Q.A. read B. write C. both read and write D. neither read nor write27.時(shí)間戳比事務(wù)T if_時(shí)間戳較小。答：小號(hào)提交之前牛逼

26、犯B. S有于T更少的指令C. S使用于T D.S。進(jìn)入系統(tǒng)牛逼以前少的數(shù)據(jù)項(xiàng)27. The timestamp of transaction S is smaller than the timestamp of transaction T if_.（什么情況下事務(wù)S的時(shí)間戳比事務(wù)T的時(shí)間戳?。〢. S commits before T commits B. S has fewer instructions than TC. S uses less data items than T D. S enters the system before T （S比T更早進(jìn)入系統(tǒng)）28.在時(shí)間戳協(xié)議，如果

27、TS（TI）<TS（TJ），串行化順序is_。A.交易鈦出現(xiàn)交易TJ前B.交易TJ出現(xiàn)交易鈦前C.由實(shí)際執(zhí)行確定D.不能確定28. In the timestamp protocol, if TS(Ti)<TS(Tj), the serializability order is_.A. transaction Ti appears before transaction TjB. transaction Tj appears before transaction TiC. determined by the actual executionD. not sure29.假設(shè)交易T22，

28、T23，T24有時(shí)間戳5,10,15，分別。如果T22請(qǐng)求由T23持有的數(shù)據(jù)項(xiàng)，那么T22將等待。如果請(qǐng)求T24 T23所舉辦的數(shù)據(jù)項(xiàng)，那么T24將回滾。這種技術(shù)被稱為_。A.并行B.饑餓C.等待模D.傷口等待29. Suppose transactions T22, T23, T24 have timestamps 5,10,15, respectively. If T22 requests a data item held by T23, then T22 will wait. If T24 requests a data items held by T23, then T24 will

29、be rolled back. This technique is called _.A. concurrent B. starvation C. wait-die D. wound-wait30. _是不是發(fā)生時(shí)檢查站執(zhí)行的操作。A.輸出到磁盤的所有修改的緩沖塊B.輸出到目前居住在主內(nèi)存中的所有日志記錄的穩(wěn)定存儲(chǔ)C.執(zhí)行所有的更新操作D.輸出到穩(wěn)定的存儲(chǔ)日志記錄<檢查點(diǎn)>30. _ is not the action to take place when checkpoints are performed.A. output onto the disk all modified

30、buffer blocksB. output onto the stable storage all log records currently residing in main memoryC. perform all update actions D. output onto stable storage a log record <checkpoint>1. A collection of interrelated data and a set of programs to access the data is called A. DatabaseB. Database sy

31、stemC. File system D. DBMS2. A major purpose of a database system is to A. enable users to access dataB. provide users with an abstract view of the dataC. assist users to store information D. check the constraints相互關(guān)聯(lián)的數(shù)據(jù)的1，一種收集和一組程序來(lái)訪問(wèn)數(shù)據(jù)被稱為A.數(shù)據(jù)庫(kù)B.數(shù)據(jù)庫(kù)系統(tǒng)C.文件系統(tǒng)D.數(shù)據(jù)庫(kù)管理系統(tǒng)2.數(shù)據(jù)庫(kù)系統(tǒng)的一個(gè)主要目的是A.使用戶能夠訪問(wèn)數(shù)據(jù)B.為用戶提供

32、數(shù)據(jù)的抽象視圖C.幫助用戶存儲(chǔ)信息D.檢查約束3. In database, how the data are actually stored is resolved at A. conceptual levelB. view level C. logical levelD. physical level4. The collection of information stored in the database at a particular moment is called A. database instance B. database scheme C. physical scheme

33、 D. data relationship5. A set of one or more attributes that, taken collectively, allow us to identify uniquely a tuple in the relation is called A. candidate key B. super key C. primary key D. foreign key3.在數(shù)據(jù)庫(kù)中，數(shù)據(jù)是如何實(shí)際存儲(chǔ)在被解析A.概念B級(jí)視圖級(jí)別C.邏輯層D.物理層4.在特定時(shí)刻存儲(chǔ)在數(shù)據(jù)庫(kù)中的信息的集合被稱為A.數(shù)據(jù)庫(kù)實(shí)例B.數(shù)據(jù)庫(kù)模式C.物理方案D.數(shù)據(jù)關(guān)系5.一組中

34、的一個(gè)或多個(gè)屬性的是，采取集體，使我們確定唯一的關(guān)系的元組被稱為A.候選鍵B.超鍵C.主鍵D.外鍵6. Physical data independence means A. application programs need not be rewritten if database schema changesB. in database, data need not to be reorganized if database schema changesC. application programs do not depend on physical database schemaD. i

35、n database, logical schema must be redesigned if physical schema changes7. Data Definition Language is used to define relational databases, includes A. define relational table, domain and user-defined typesB. define consistency constraints like domain constraints, referential integrity etc.C. both A

36、 and B D. neither A nor B8. In following terms, is proper.A. relation is a table in relational database B. attribute is a row of a tableC. tuple means a column of a table D. each table must has many rows.6物理數(shù)據(jù)獨(dú)立性的手段A.應(yīng)用程序不需要，如果數(shù)據(jù)庫(kù)架構(gòu)更改改寫B(tài).在數(shù)據(jù)庫(kù)中，數(shù)據(jù)不需要進(jìn)行重組，如果數(shù)據(jù)庫(kù)架構(gòu)更改C.應(yīng)用程序不依賴于物理數(shù)據(jù)庫(kù)架構(gòu)D.在數(shù)據(jù)庫(kù)中，邏輯模式必須的，如果物理

37、模式的變化重新設(shè)計(jì)7.數(shù)據(jù)定義語(yǔ)言來(lái)定義關(guān)系數(shù)據(jù)庫(kù)，包括A.定義關(guān)系表，域和用戶定義類型B.這樣定義域約束，參照完整性等一致性約束C. A和B D. A和B都8.下列術(shù)語(yǔ)，是正確的。答關(guān)系是在關(guān)系數(shù)據(jù)庫(kù)B屬性的表是一個(gè)行的表C.元組指表D.每個(gè)表必須有許多行的一列。9. A relation r1 may include among its attributes, a subset of attributes named as S, the primary key of another relation r2, is a correct description.A. S is a foreig

38、n key of r2B. S is a foreign key of r1C. r1 is referenced relation in this foreign key dependenceD. S is referenced relation in this foreign key dependence10. Stored Procedure A. is just the same as Stored Function B. is a subroutine available to applications that access a relational database system

39、C. can be executed on database server or called by application server.D. is a transaction that must be treated as a whole.9甲關(guān)系R1可以包括在其屬性，命名為S，另一種關(guān)系r2中的主鍵，屬性的子集是一個(gè)正確的描述。答：A .S為R2 B. S的外鍵是R1的外鍵C. R1被引用的關(guān)系在這個(gè)外鍵的依賴D. S被引用的關(guān)系，在這個(gè)外鍵的依賴10.存儲(chǔ)過(guò)程答：A是一樣的存儲(chǔ)函數(shù)B.提供一個(gè)子程序訪問(wèn)一個(gè)關(guān)系數(shù)據(jù)庫(kù)系統(tǒng)的應(yīng)用程序C.可以數(shù)據(jù)庫(kù)服務(wù)器上執(zhí)行或調(diào)用應(yīng)用程序服務(wù)器。D.是必

40、須被視為一個(gè)整體的交易。11. Let A, B, C and D be attributes, in the following relational algebra expressions, is not a relation.A. R(A´B´C´D)B.R(A)C. R(A,B) D. R(A,B) ´ S(C,D)12. is not contained in the SQL language?A. Integrity B. Query execution plan C. Transaction control D. Authorization

41、13. Among the following sentences about trigger, is wrong.A. trigger is a special kind of stored procedure B. trigger is different to stored procedure in that it is auto-executed and with no parameters.C. triggers can be used to maintain data consistenceD. in triggers, temporary table deleted and in

42、serted can be queried and updated.11設(shè)A，B，C和D是屬性，在下面的關(guān)系代數(shù)表達(dá)式，是不是一個(gè)關(guān)系。A. R（A´B´C´D）BR（A）C. R（A，B），D。R（A，B）´S（C，D）12.不包含在SQL語(yǔ)言？A.誠(chéng)信B.查詢執(zhí)行計(jì)劃C.事務(wù)控制D.授權(quán)13.在有關(guān)觸發(fā)下面的句子，是錯(cuò)誤的。答：觸發(fā)器是一種特殊類型的存儲(chǔ)過(guò)程B.觸發(fā)不同于存儲(chǔ)過(guò)程中，它是自動(dòng)執(zhí)行，并且不帶參數(shù)。C.觸發(fā)器還可以保持?jǐn)?shù)據(jù)的一致性DIN觸發(fā)器，臨時(shí)表中刪除和插入可以查詢和更新。14. When a view is created, mus

43、t be stored in data dictionary.A. the corresponding select sentenceB. the definition of the viewC. the data of the viewD. the definition of tables used to define the view15. In SQL, is an equivalent operator to “NOT IN”A. <>ALL B. <> SOME C. =ALL D. =SOME16. In SQL, “CREATE INDEX” is use

44、d to create a A. relation Schema B. virtual relationC. a secondary table used to accelerate query D. database schema當(dāng)創(chuàng)建一個(gè)圖，必須存儲(chǔ)在數(shù)據(jù)字典。是的。視圖的對(duì)應(yīng)的選擇句子B中的定義C.視圖D.用來(lái)定義視圖表的定義的數(shù)據(jù)15.在SQL中，是一個(gè)等效操作員“NOT IN”A.<> ALL B.<> SOME C.= ALL D.=部分16.在SQL中，“CREATE INDEX”用于創(chuàng)建一個(gè)A.關(guān)系模式B.虛擬關(guān)系C.輔助表用于加速查詢DI。數(shù)據(jù)庫(kù)模式1

45、7. Given the following tables:StudSCSnoSnameS#C#Grade1Smith11802Jones25903Smith261004BOB3130Which of the following statements removes the rows from the Stud table that have courses in the SC table?A. DELETE FROM Stud WHERE S# IN (SELECT Sno FROM SC);B. DELETE FROM Stud WHERE S# IN (SELECT S# FROM SC

46、);C. DELETE FROM Stud WHERE Sno IN (SELECT S# FROM SC);D. DELETE FROM Stud WHERE Sno IN (SELECT Sno FROM SC); 18. A m:n relationship in ER model can be transferred into a relation with its primary key composed of A. primary key of relation at m side B. primary key of relation at n sideC. attributes

47、of the relationship itselfD. primary keys of relation at both sides以下哪項(xiàng)陳述將刪除梭哈表已經(jīng)在SC表課程行？A. DELETE FROM梭哈其中SIN（SELECT沒(méi)有來(lái)自SC）;B. DELETE FROM梭哈其中SIN（選SFROM SC）;C. DELETE FROM梭哈WHERE斯諾IN（選SFROM SC）;D. DELETE FROM梭哈WHERE斯諾IN（SELECT斯諾FROM SC）;18. M：N的ER模型關(guān)系可以轉(zhuǎn)移到一個(gè)關(guān)系其組成的主鍵關(guān)系的關(guān)系m的B面的主鍵為N A面主鍵關(guān)系本身，在其兩側(cè)C.屬性關(guān)

48、系D.主鍵19. In conceptual-design phase, is the most common tools.A. Relation model B. Network model C. ER model D. OO model20. In database logical-design phase, must be given.A. logical schema of databaseB. inner Schema of databaseC. dataflow graph D. user Schema of database21. Techniques for implement

49、ing integrity constraints are A. declarative integrity constraintsB. database triggersC.data manipulation languageD. Both A and B在概念設(shè)計(jì)階段，是最常用的工具。A.關(guān)系模型B.網(wǎng)絡(luò)模型C. ER模型D.面向?qū)ο竽Ｐ?0.在數(shù)據(jù)庫(kù)邏輯設(shè)計(jì)階段，必須考慮。數(shù)據(jù)庫(kù)數(shù)據(jù)庫(kù)B.內(nèi)部架構(gòu)的A.邏輯模式數(shù)據(jù)庫(kù)C.數(shù)據(jù)流圖D.用戶模式21.技術(shù)實(shí)現(xiàn)完整性約束A.聲明完整性約束B.數(shù)據(jù)庫(kù)觸發(fā)器C.數(shù)據(jù)操縱語(yǔ)言D. A和B22. In database design, Normaliz

50、ation is used to avoid insert exception, delete exception and A.data inconsistence B. data redundancyC. data lost D. improper schema23. Relation among Normal Form is A. 1NFÌ 3NF ÌBCNFB. 3NFÌ 1NF ÌBCNFC. BCNFÌ 3NF Ì1NFD. 1NFÌ BCNF Ì3NF24 Let R be a relation sch

51、ema, and Attribute A,BÎR, A®B means relationships between A and B are A. many-to-1 B. 1-to-many C. many-to-many D. none of A, B and C在數(shù)據(jù)庫(kù)的設(shè)計(jì)，標(biāo)準(zhǔn)化是為了避免插入異常，刪除異常，A.數(shù)據(jù)不一致BY。數(shù)據(jù)冗余C.數(shù)據(jù)丟失D.不正當(dāng)模式范式之中23.關(guān)系A(chǔ).1NFÌ3NFÌBCNFB.3NFÌ1NFÌBCNFC.BCNFÌ3NFÌ1NFD.1NFÌBCNFÌ3N

52、F24設(shè)R是一個(gè)關(guān)系模式，而屬性A，BÎR，A®B意味著A和B之間的關(guān)系是A.多對(duì)1 B.1對(duì)多C.多到很多D.無(wú)A，B和C25. In the following rules about functional dependency, is correct.A. X®Y if XÍ Y B. WX®Z if X®Y and WY®ZC. X®Z, Y®Z if XY®ZD. X®Y if XÇ Y =Æ26. is the first state in a life

53、 cycle of a transaction.A. Committed B. Active C. Failed D. Aborted27. Which of the following pairs of instructions conflict?A. write(B), write(B) B. read(A), write(B) C. write(A), read(B) D. read(A), read(A) 28. Which of the following pairs of locks are compatible?A. Exclusive-lock(B), Shared-lock(

54、B) B. Exclusive-lock(B), Exclusive -lock(B)C. Shared-lock(A), Exclusive-lock(A) D. Shared-lock(A), Shared-lock(A) 在關(guān)于函數(shù)依賴以下的規(guī)則，是正確的。如果XÍÿB.X®X如果X®Y和WY®ZA.X®YC.X®Z，如果Y®ZXY®ZD.X®Y如果XÇY =Æ26.在一個(gè)交易的生命周期的第一狀態(tài)。A.承諾B.主動(dòng)C.失敗D.中止27.下列哪項(xiàng)指令對(duì)矛盾？A.寫（B），

55、寫（B）B.讀?。ˋ），寫（B）C.寫（A），讀（B）D.讀（A），閱讀（一）28.下列哪項(xiàng)對(duì)鎖的兼容？A.獨(dú)占鎖（B），共享鎖（B）B.獨(dú)占鎖（B），獨(dú)家-lock（B）C.共享鎖（A），獨(dú)占鎖（A）D.共享鎖（A），共享鎖（A）29. is a mythical form of storage that survives all failures.A. volatile storage B. non-volatile storage C. stable storage D. non-stable storage30.To authorize query privilege of table s to database user Wang, and permit Wang to authorize the privilege to others, The SQL sente