Summary of multiple choice questions in the 2022 database of tyut Taiyuan University of Technology

The first 1 Chapter

One 、 Single topic selection

1、 database （DataBase,DB） It is stored on the computer （  A structured ） Related data sets .

2、 The information model that reflects entities and their relationships in the real world is （   Physical connection （ER） Model ）

3、 Student entity （ type ） And course selection entity （ type ） The connection between them is （  Many to many   ） contact

4、 Data management technology has experienced ４ Stages of development , Among them, the highest data independence is （  Database system ） Stage .

5、 The main purpose of applying database technology is to （   Solve the problem of data sharing   ）

6、 In database management system ,（  Interactive query module   ） It is not a function module of database access

7、 database （DB）、 Database system （DBS） And database management system （DBMS） The relationship between （ DBS Include DB and DBMS ）.

8、 The conceptual model is the first level of abstraction in the real world , The most famous model of this kind is （ Entity - Connection model ）

9、 at present , The most commonly used logical data model of database management system is （ relational model ）

10、 Of the following four , What is not characteristic of a database system is （ High data redundancy ）

11、 The three elements of the data model are （ data structure 、 Data manipulation 、 Data integrity constraints  ）

12、 The three-level structure of the database is from the inside to the outside 3 The three levels are （ Internal mode 、 Pattern 、 External mode ）

13、 The following correct description of the database system is （ The database system reduces data redundancy ）.

14、 The independence of database system refers to （ It will not affect the application due to the changes of the system storage structure and data logical structure ）

15、 The logical independence of data means （ Keep the external mode unchanged when the mode changes    ）

16、 The physical independence of data means （ Keep the mode unchanged when the internal mode changes ）

17、 The company has many departments and staff , Each employee can only belong to one department , A department can have more than one employee , The contact type from department to employee is （ One to many ）

18、 Save all multiple depositors , Depositors deposit between savings offices , Between depositors and savings offices （ Many to many contact ）.

19、 Describes the global logical structure and characteristics of all data in a database （ Pattern ）.

20、 The description of the data view used by a single user is called （ External mode ）

21、 Subscheme DDL Used to describe the （ The local logical structure of the database ）

Two 、 Completion

1、 Data processing （Data Processing） It's about data 　　 collection 、 Storage 、 retrieval 、 machining 、 Transformation and transmission 　　　　　　     The process of .

2、 Database management system DBMS The functions realized by the program can be divided into the following 4 part ： Language compiler handler 、 System operation control program 、 System establishment and maintenance procedures   　 And data dictionary .

3、 The data model that represents entity types and relationships between entities in the tree structure is called     hierarchical model             

4、 The relational model is a simple       Two-dimensional table   structure

5、 The object-oriented method is abstract 、 encapsulation 、   Inheritance and polymorphism      Other characteristics

6、 The architecture outside the database system is divided into centralized 、 Parallel 、 Distributed and client / Server structure 4 Kind of .

7、 The database system is generally composed of （ database ）、（ Database management system ）、（ Applications ） and （ Database administrator ） form .

8、 The database is stored in the computer for a long time 、 Yes （ organization ） Of 、 can （ share ） Data set for .

9、DBMS Express （DataBase Management System）, It is located in （ user ） and （ operating system ） Between a layer of data management software .

10、 The relations between entities can be abstracted into three categories , They are （ one-on-one ）、（ One to many ） and （ Many to many ）.

11、 The three elements of a data model include （ data structure ）、（ Data manipulation ） and （ Data integrity constraints ） In the third part of .

12、 According to the application purpose of the data model , The data model is divided into （ conceptual model ）、（ logical model ） and （ The physical model ） etc. .

13、 Name according to the type of data structure , The logical model is divided into （ relational model ）、（ hierarchical model ） and （ Mesh model ） etc. .

14、E-R In the figure ,（ rectangular ） Represents an entity ,（ The ellipse ） Represents the property ,（ The diamond ） Represents the relationship between entities .

In various data models , The hierarchical model uses （ Tree structure ） Represents the entity type and the relationship between entities , Mesh model use （ Directed graph structure ） Represents the entity type and the relationship between entities , The relational model uses （ Two dimensional table structure ） Represents the entity type and the relationship between entities .

The first 2 Chapter

One 、 Single topic selection

1、 What's wrong with the relational model is （ Without connection operation DBMS It can also be a relational database system ）

2、 Special relational operations that relational database management system should be able to implement include （ choice 、 Projection 、 Connect ）

3、 Cartesian product is （ To the horizontal direction of the relationship 　） Carry out operations

4、 In the relational model , One keyword is （ It can be composed of one or more attributes whose values can uniquely identify any record in the relational schema ）

5、 Natural connection is an effective way to form new relationships . In general , When it comes to relationships R and S When using natural connections , requirement R and S Containing one or more common （ attribute ）

6、 The most time-consuming operation in relational operation is （ The cartesian product ）

7、 Any attribute of a relational schema （ Can not be further divided ）

8、 In the traditional set operation of relational algebra , Suppose there is a relationship R and S, The result of operation is W. If W The records in belong to R, And belongs to S, be W by （ hand over ） Result of operation

9、 Data integrity constraints mainly refer to （　 Value constraints and structural constraints ）

10、 The five basic operations of relational algebra are （ and 、 selection 、 Bad 、 Cartesian product 、 Projection 　）

11、 The following statements about null values are incorrect （ use =NULL Query the records whose specified column is null 　）

12、 Natural connection is （ Not only to the horizontal direction of the relationship, but also to the vertical direction of the relationship 　） Carry out operations

13、 About relational models , What's wrong with the following statement is （ The data in the relationship can be arbitrary ）

14、 About relationships , What's wrong with the following statement is （ Attributes in tuples are ordered ）

15、 Get some columns of the relationship when querying the relationship , And cancel the relation operation of repeated tuples as （ Projection operation ）

16、 According to the entity integrity rules of the relationship pattern , The primary code attribute of a relationship （ Not allowed to be empty ）

17、 In relation mode R（R#,RN,S#） and S（S#,SN,SD） in ,R Is the primary key R#,S Is the primary key S#, be S# stay R called （ Outer code ）.

18、“ Achievements in 0-100 Between ” What kind of integrity constraint does this constraint belong to （ User defined integrity constraints ）

19、 Relationship R As shown in the figure below ,a1 The image set of is ：{（b1,c1）,（b2,c3）}

A	B	C
a1	b1	c1
a1	b2	c3
a2	b1	c2

20、 When the relationship R and S When making a natural connection , Can handle R and S The operation of putting the tuples that should be discarded into the result set is （ Complete external connection ）

21、 Relationship R and S When making a natural connection , Can handle R The operation of putting the floating tuple of into the result set is （ The left outer join ）

22、 Existing relationship table ： Student （ Dormitory number , Dormitory address , Student number , full name , major , Date of birth ）, Its main code is （ Student number ）

23、 The two relations for natural connection operation must have （ Public attribute       ）

24、 About foreign keys , The following statement is correct （ Foreign keys can have different names from the corresponding primary keys , As long as it is defined on the same domain ）

Two 、 Completion

1、 The definition format of a relational schema is Relationship name ( Property name 1, Property name 2,…, Property name n), As a student （ Student number , full name , Gender , major ）

2、 The definition of a relational schema mainly includes ： Relationship name , Property name , Attribute types , Attribute length , keyword

3、 In relational algebra operations , The traditional set operations are ： The cartesian product , and , hand over , Bad

4、 In relational algebra operations , The basic operation is ： and , Bad , The cartesian product , Projection , choice

5、 In relational algebra operations , Special relational operations are ： choice , Projection , Connect , except

6、 Two kinds of operations based on Mathematics in relational database are   Relational algebra       and     Relationship calculus    

7、 The objects used for integrity constraints are ： Column , Tuples （ Record ）, Relationship

8、 Relational algebra expresses queries by operations on Relations , And relationship calculus uses Predicate expression Of the query , It is divided into 　 Tuple relations 　 Calculus and 　 Domain relations There are two kinds of calculus .

9、 Traditional collections “ hand over 、 and 、 Bad ” When an operation is applied to two relationships , These two relationships 　 Number of attributes 　　　 Must be equal ,　 Corresponding attribute value 　　　　 Must be from the same domain .

10、 Two types of relational operations in relational databases are ： Traditional relational operations , Special relational operations

11、 Relationships represented in an entity （ Data sheet ） in , call The attribute or attribute group that can uniquely identify the entity keyword .

12、 The relational model consists of relational data structure 、 Relationship operation and relationship integrity constraints consist of three parts

13、 Relationship integrity constraints include primary key constraints 、 Foreign key constraints and user-defined integrity constraints

14、 Queries in relational algebra include the union of Relations 、 hand over 、 Bad 、 Cartesian product 、 choice 、 Projection 、 Operations such as connection and division .

The first 3 Chapter

One 、 Single topic selection

1、SQL Language is （  relational database   ） Language

2、SQL Server 2019 It's based on （C/S Pattern     ） The relational database management system .

3、SQL Server The authentication modes adopted mainly include （   Windows Authentication mode and mixed mode ）

4、SQL Server The documents include : Master data file 、 auxiliary （ Time ） Data files and （ Log files   ）

5、 below （ System object ） Do not belong to SQL Server Of Master The information contained in the database

Two 、 Completion

1、SQL Server 2019 After installation , The system will create 4 A visible system database , Namely master、model、msdb、tempdb、; It also creates a read-only database resource

2、SQL Server 2019 There are mainly （ System 、 user 、 Example type ） The database of .

3、SQL Server The programming language in is （T-SQL） Language , It is a non procedural high-level language , Its basic ingredient is （SQL）.

4、“< >”（ Angle brackets ） is “      Mandatory         term ”, You can't default

5、SQL Language is both      Self contained        Language —— Input directly on the terminal keyboard SQL Command to operate the database , again    The embedded          Language —— take SQL Statements are embedded in high-level languages for data processing .

6、 Multiline comment statements are also called block comment statements , Usually placed in       Program （ block ）       In front of , For program functions 、 Description of characteristics and precautions , With /* Start with      */    end

The first 4 Chapter

One 、 Single topic selection

1、 The following SQL In the sentence , Modifying the table structure is ( ALTER )

2、 Delete the SQL The sentence is （ DROP  ）

3、 stay SELECT In the sentence , The clauses used to implement data grouping statistics are ( GROUP BY Clause    )

4、SQL In language , The statement to realize data query is （  ．SELECT  ） Language

5、 Which of the following operations cannot lead to subqueries .(  LIKE)

6、 Based on 3 A relationship ：S( Student number , full name , Gender , Age )、C( Course no. , Course name , The teacher )、 SC( Student number , Course no. , achievement ), If it is required to find students whose average score is greater than 80 Student number and average score , Listed below SQL sentence , The right is （ C）.

A．SELECT Student number , AVG( achievement ) FROM SC WHERE AVG( achievement )>80

B．SELECT Student number , AVG( achievement ) FROM SC WHERE AVG( achievement )>80 GROUP BY Student number

C．SELECT Student number , AVG( achievement ) FROM SC GROUP BY Student number HAVING AVG( achievement )>80

D．SELECT Student number , achievement FROM SC GROUP BY Student number HAVING AVG( achievement )>80

7、 The following SQL In the sentence , The right is （B） 

notes ：Where A conditional expression in a sentence cannot use an aggregate function

A．SELECT S#, SNAME FROM SC GROUP BY S#

B．SELECT S# FROM SC GROUP BY S# HAVING COUNT(*)>3

C．SELECT S# FROM SC GROUP BY S# WHERE COUNT(*)>3

D．SELECT S# FROM SC WHERE COUNT(*)>3 GROUP BY S#

8、 Based on 3 A relationship ：S( Student number , full name , Gender , Age )、C( Course no. , Course name , The teacher )、 SC( Student number , Course no. , achievement ), If you need to find elective “ Database technology ” Names and grades of students in this course , Relationships will be used （ S、SC and C）

9、SQL Language can be used in two ways , They are interactive SQL and （ The embedded SQL   ）

10、 What can't be done on a view is （ Define a new basic table on the view ）

11、 After the database is created , In this database, you can store （   Multiple  ） Data sheet with similar business .

12、SELECT The result of statement execution is （   surface  ）.

13、SQL In language , The statement to realize data deletion is （DELETE ）

Two 、 Completion

1、SQL The full Chinese name is     Structured query language           

2、 stay SQL In the sentence , The statement defining the database is    CREATE DATABASE         

3、 stay SQL In the sentence , The statement to create a table structure is     CREATE TABLE

4、 stay SQL In the sentence , The statement to modify the table structure is      ALTER TABLE          

5、 stay SQL in ,（CREATE TABLE） Statement to create tables and declare integrity constraints . If you want to be a base

Columns and integrity constraints are added to this table , You should use （ALTER TABLE) sentence . Delete the definition of the table and in the table

Data and index , The statement that should be used is （DROP TABLE）.

6、. stay SQL In the query statement of , Use （FROM） Clause data source , Use （WHERE) Clause selection parameter

And the data line of the operation , Use （SELECT） Clause specifies the target column . You can use （GROUP BY） Clause combined with

Aggregate function for grouping statistics . If sorting the query results, you can use (ORDER BY） Clause

7、 Delete the SQL The sentence is   DROP DATABASE    , The command statement used to delete data in the data table is         DELETE FROM < Data table name >      .

8、SQL use INSERT Statement to insert data .INSERT There are two forms of statements ：

Namely Insert tuples （ Record ） and Insert query results .

9、 View is defined in （ Basic table ） Virtual table above , You can also insert views 、 modify 、 Delete and query operations .

But views do not store data , All operations on the view should eventually be converted to （ Basic table ） The operation of

10、SELECT In the sentence , The conditional expression is expressed in   WHERE Clause , For grouping   GROUP BY Clause , For sorting              ORDER BY Clause .

The fifth chapter

One 、 Single topic selection

1、 The following description of the index is incorrect （ Index is external mode    ）

2、SQL There are two ways to query ： Scan the table row by row and query （ Indexes ）

3、 Indexes are mainly divided into ： Clustered indexes and （ Non aggregation ） Indexes

4、 stay SQL In language , The statement to delete the index is （DROP INDEX < Table name > < Index name >）.

5、 After the view is created , The data dictionary stores （ View definition ）

6、 In the database physical design phase , You need to consider building an appropriate index for the relationship , Description of indexing , The following statement is correct ( For those who often appear in WHERE Attribute in clause , Consider indexing    ).

Two 、 Completion

1、 utilize SQL Statement CREATE  UNIQUE INDEX  < Index name > ON  < Table name >  ( < Name > ,DESC)

  Command to create a unique descending index

2、 A view is a virtual table , It's from Basic table   Or tables exported from other views , Users can use views based on surface      The data of .

3、 There are four types of views . In addition to user-defined standard views ,SQL Server 2019 Also provide

了     Index view    、    Zone view     、 Special types of views such as system views .

4、 View creation and   Delete   Does not affect the base table , however , Of view content   to update   Directly affect the base table .

5、SQL The language supports three-level schema structure of database . stay SQL in , The outer mode corresponds to View And some basic tables , The schema corresponds to all of the basic tables , The inner mode corresponds to storing files

The first 6 Chapter

One 、 Single topic selection

1、 stay SQL SERVER in , Execute a stored procedure with parameters , The right way is （ The process of Parameters    ）

2、（  trigger   ） Allow the user to define a set of operations , These operations are performed by deleting the specified table 、 Insert and update commands to execute or trigger .

3、SQL Server Two temporary tables are created for each trigger , They are （  Inserted and Deleted  ）

4、 Entity integrity requires that the primary attribute cannot be null , This is usually done by （ Define a primary key to ensure ）

5、 The following SQL In the sentence , The statements that can implement referential integrity control are （FOREIGN KEY ）

6、 Use CREATE TABLE STU (NO CHAR(4) NOT NULL, NAME CHAR(8) NOT NULL, SEX CHAR(2), AGE INT ) Created table STU , Which of the following statements can be inserted into the table .（ INSERT INTO STU VALUES (‘1031’,’ Zhang hua ’,NULL,NULL)）

7、 Which of the following actions will not activate the trigger .( SELECT )

8、 stay SQL The authorized operation in the language is through （GRANT　） Statement implementation

9、 If the relationship R(A,B,C) The main code is A, Relationship S(D,A) The main code is D, The outer code is A, Here's the relationship S Which tuple in violates the integrity constraint ？（(3, 3) ）.

                            R                        S

A	B	C		D	A
1 2	2 1	3 3		1 2 3 4	2 Null 3 1

The first 7 Chapter

One 、 Single topic selection

1、SQL Server The single line comment statement provided uses （ -- ） The first line

2、 For multiline comments , You must use comment character pairs （ /*） Start commenting , Use end comment character pairs （ */） End note .

3、SQL Sever in , What symbol does the global variable begin with （  @@）

4、 The following identifiers can be used as local variables are （ @Myvar ）

5、 The function used to remove spaces at the end of a string is （ RTRIM ）

6、 The following T-SQL The syntax error in the sentence is （ DELETE * FROM AAA ）

Two 、 Completion

1、SQL Server The programming language in is ＿T-SQL Language , It is a non procedural high-level language , Its basic ingredient is ＿SQL sentence ＿.

2、 An operator is a symbol , Used to specify the operation to be performed in one or more expressions ,SQL Server 2019 Regular use （ Assignment operator 、 Arithmetic operator 、 Bitwise operators 、 String operators 、 Comparison operator 、 Logical operators

） And unary operators .

3、T-SQL The control structures provided are ：（IF…ELSE Single branch ,CASE Multiple branches ,WHILE Loop structure ,GOTO sentence ,WAITFOR Statement and RETURN sentence

）

4、 stay SQL Server in , Its variables are divided into two kinds ： One is ＿ local variable ＿, The other is ＿ Global variables ＿.

5、 Enclosed in quotation marks （“ ”） Or square brackets （［］） The identifier in is called Define the identifier ＿

6、 function LEFT(' abcdef', 2) The result is  ‘ab’ ＿

7、 stay T-SQL in , The start tag keyword of each block is （BEGIN）, Its end tag keyword is （END）

8、 Generally, it can be used ＿GO＿ Command to identify T-SQL End of batch .

The first 8 Chapter

One 、 Single topic selection

1、 The following is about login account 、 What is wrong with users and roles is ( The user does not have to be associated with the login account   )

2、 Database management system usually provides authorization function to control the access rights of different users to data , This is mainly to realize the of database （ Security   ）.

3、 If you have any 3 Users U1,U2,U3, Relationship R, Then the following does not meet SQL The statement of permission granting and recycling of is （ Revoke Update On R To U3 ）.

4、 When there is a breakdown , According to the field data content 、 Pre failure images of log files and （ Log files ） To restore the state of the system .

5、 If business T Data pair R Already added X lock , Then other pairs of data R（ No locks   ）.

6、 What data inconsistencies will be caused by concurrent operations （ Lost update 、 It can't be read repeatedly 、 Dirty reading 、 Fantasy reading ）

7、 It is widely used to solve the problem of data inconsistency caused by concurrent operations （ The blockade        ）.

8、 A company uses SQL Server 2019 Manage company data , Now the database administrator hopes that for important databases 202108_DB Back up the transaction log , Before that, he should ensure that the restore mode of the database is （  Full recovery mode or bulk log recovery mode ）.

9、 If the system is running , For some reason , Causing the system to stop running , Cause the transaction to terminate in an uncontrolled manner during execution , At this time, the information in memory is lost , The data stored in external memory is not affected , This situation is called （ System failure    ）.

10、 Make a transaction wait forever , The phenomenon that cannot be implemented is called （ Live lock      ）

11、 About “ Deadlock ” , What is correct in the following statement is （ Only when concurrent operations occur , Before a deadlock can occur   ）

Two 、 Completion

1、 The core and key of database security is _ Data security ___

2、SQL Server 2019 Security management of can be divided into 3 Level ：（ Operating system level 、 SQL Server Server level 、 Database level ）

3、 The purpose of backup is in case the database is destroyed , It can be fixed , The main types of database backup are ：（ Full backup 、 Full differential backup 、 Partial backup 、 Partial differential backup 、 File and filegroup backup 、 File differential backup 、 Transaction log backup ;）

4、 Various failures may occur during the operation of the database , These faults can be divided into 3 class ：（ Transaction failure 、 System failure 、 Media failure ）

5、 Data recovery operations usually have 3 Types ：（ Complete recovery 、 Individual file recovery 、 Redirect recovery ;）

6、 stay SQL In language , For database security , Set the statement to control the access of data , Authorize users to use _ Grant ___ sentence , Revoke the granted permission to use Revoke ___ sentence

7、 Transaction failure 、 The recovery of system failure is made by ___ System auto ___ Accomplished , The recovery of media failure is made by __ DBA Perform recovery operations ___ Accomplished .

8、 Users can set the permissions of the server and database , Mainly involves 3 Species jurisdiction ： Namely （ Server permissions 、 Database object permissions 、 Database permissions ）

9、 The main method of concurrency control is _ The blockade _ Mechanism , The most typical types are __ Shared lock ____ and ___ Exclusive lock __ Two kinds of .

10、 Object permission refers to the user's access and operation permission based on the database object level , share 5 Kind of ：Select、Insert、Delete、（Update、 Execute）

11、__ Full differential backup _ Only record the data that has changed since the last full database backup .

The first 9 Chapter

One 、 Single topic selection

1、 If there is a functional dependency X→Y, And right X A true subset of X’, Yes X’→Y establish , said （．Y Some functions depend on X ）

2、 if X→Y and Y→Z In relation mode R On the establishment of , be X→Z stay R It is also established. . This reasoning rule is called （ Transfer rules ）.

3、 If the relational pattern R Middle attribute A It only appears on the left of the functional dependency , be A by （L Class properties ）

4、 set up F Is the minimal functional dependency set of a relational pattern . The following about F That's what I'm saying , The wrong is （F The left part of each function dependency in must be a single attribute ）    

5、 There's a relationship model R(X,Y,Z), Its F={Y→Z,Y→X,X→YZ}, Then the relationship pattern belongs to at least （BC normal form ）

6、 In relational mode , Patterns that satisfy the second paradigm （ It must be the first paradigm ）

7、 There's a relational model ： Borrow books （ Book number , Title , Inventory , Reader number , Borrowing date , Return date ), Let a reader borrow the same book many times , But for a book （ Use the book number to uniquely identify ） You can't borrow more than one book at the same time . The primary key of this relational schema is （（ Book number , Reader number , Borrowing date ） ）.    

8、 The normalization of relational database is to solve the problem of （ Insert 、 Delete 、 Update exceptions and data redundancy ） Introduced by the problem of

9、 Each component in the relational schema is an inseparable data item , Then the relationship pattern belongs to (1NF    )

10、 if R∈2NF, be R Each ( The non primary attribute is completely dependent on the code )

11、 It eliminates the dependence of non primary attribute on code transfer function 2NF Relationship model of , Must belong to (3NF )

Two 、 Completion

1、 If the relational pattern R∈2NF, be R There must be no non primary attribute pair primary key （ code ） Of __ Part of the function depends on _ Function dependency .

2、 In relation mode R in , If you have any X→Y, And ZÍY, be X→Z stay R It is also established. , The reasoning rule is Armstrong In axiomatic systems __ Break down the rules .

3、 The relational tables in the relational database at least meet _ First of all _ Paradigm requires

4、 If the relational pattern R Primary key of （ code ） Contains only one attribute , be R At least belong to the __ Two _ normal form .

5、 The relationship pattern is in the process of normalization , If decomposition is required to preserve functional dependencies , Then the decomposed mode can achieve 3NF, But not necessarily BCNF.

6、 If there are functional dependencies X→Y, And right X Any proper subset of X’, There are X’！->Y, said _Y Yes X Completely function dependent

The first 10 Chapter

One 、 choice question

1、 Data flow diagram DFD It's from “ data ” and “ Handle ” A graphical representation of data processing in two aspects , This method is mainly used in database design （   Demand analysis stage      ）.

2、 In database design , take E-R The transformation from graph to relational data model is mainly （  Logic design stage   ） Work completed in stage .

3、 When designing the logical structure of the database , The common basis for reviewing whether the design is reasonable is （ Normalization theory ）

4、 In database design , The user sub model design is （  Conceptual structure design stage   ） What should be done in this stage

5、 In this part E-R The graph is merged into a global E-R Picture time , There may be some conflicts . The following conflicts are not merged E-R The picture conflicts with （  Grammar conflict   ）.

6、 Set entity A And entities B There is a one to many connection . In the following logical structure design methods , The most reasonable thing is （  Entity A And entities B Each corresponds to a relationship pattern , And the foreign key is placed on the entity B In the relationship model   ）.

7、 There is a relationship model to describe the book publishing situation ： published （ Book number , Publication date , Print quantity ）, Suppose a book can be published many times , Each publication has a number of publications . The candidate keys for this relational schema are （（ Book number , Publication date ）    ）

8、 The focus of the review of the physical design of the database is （  Spatiotemporal efficiency   ）

9、 The following is not part of the physical structure design of the database （ Determine the database table structure    ）

10、 The following work that does not belong to the database implementation stage is （ Expand system functions    ）

11、 In database design , take E-R The process of transforming a graph into a relational schema belongs to ( Logic design stage )

12、 In relational mode , Represents inter entity M：N The connection is through the addition of (  Relationship implementation )

13、 from E-R When transforming a model into a relational model , One M:N The connection is transformed into a relational model , The key word for this relational schema is ( M The keyword of the end entity is the same as N Combination of keywords of end entities )

14、 stay E-R In the model , If there is 3 Different entity types ,2 individual M：N contact , according to E-R Rules for converting models into relational models , The number of conversions to relationships is .( 5 )

Two 、 Completion

1、 Generally, database system design is divided into （ Demand analysis , The structure design , Behavioral design , Database implementation

、 Database operation and maintenance ） Six stages .

2、 Database structure design includes _（ Conceptual structural design , Logical structure design , Physical structure design

）_ Three processes

3、 The data flow diagram represents the _ data __ and __ Handle The relationship between

4、 In the data dictionary _ Data item （ Or attributes ）____ Is an indivisible unit of data

5、 In database design , In the requirement analysis stage, document the data requirements , Including data items 、 data structure 、 Data flow 、 Description of data storage and data processing process , This document is usually called ___ The data dictionary

6、 The result of conceptual design is to get a relationship with _ whatever DBMS___ Irrelevant model .

7、 take E-R The organization level data model supported by a database management system is _ Logic （ structure ）___ Work completed in the design stage .

8、 In the process of local E-R Possible conflicts during the merging of graphs are （ Property conflict , name conflict , Structural conflict

）

9、 use E-R The conceptual structure design of the method usually includes （ Design part E-R chart , Design the whole picture E-R chart ,  Optimize the overall situation E-R chart

） Three steps .

10、 According to the application requirements, the work of establishing indexes on tables and attributes is designed in the database __ physical design

____ Phase completed .