A deductive database approach to automated geometry theorem proving and discovering

数据库选择题答案1. A relational database management system (RDBMS) is a system that manages relational databases and allows users to interact with data stored in these databases. It provides a structured way to organize and manage data, making it easier to query, update, and analyze.2. Structured Query Language (SQL) is a programming language used to manage and manipulate data in a relational database. It provides a standardized way to retrieve, insert, update, and delete data from databases.3. The main components of a relational database system include:- Database: A collection of related data organized and stored in a structured format.- Tables: A database consists of one or more tables, which hold the data.- Rows: Each row in a table represents a record or instance of data.- Columns: Each column in a table represents a specific attribute or field of the data.- Primary key: A primary key is a unique identifier for each record in a table.- Foreign key: A foreign key is a reference to a primary key in another table, establishing a relationship between the two tables.4. The advantages of using a relational database management system are:- Data integrity: RDBMS ensures data integrity by enforcing constraints and rules on data manipulation.- Data consistency: RDBMS maintains a consistent view of data across the database, ensuring that changes are propagated correctly.- Data security: RDBMS provides features like access control and encryption to protect data from unauthorized access.- Scalability: RDBMS allows for the efficient management of large amounts of data and can scale to accommodate growing needs.- Query flexibility: SQL provides a powerful and flexible way to query and retrieve data from databases.- Data independence: RDBMS separates the physical and logical representation of data, allowing for easier management and modifications.5. When choosing a database system, several factors need to be considered:- Data requirements: Assess the type of data, volume, and complexity to determine the most suitable database system.- Performance: Consider the expected workload and performance requirements to select a database system that can handle the anticipated load.- Scalability: Determine if the database system can scale to accommodate future growth in data volume and user concurrency.- Availability: Evaluate the high availability features andbackup/recovery mechanisms provided by the database system.- Cost: Consider the licensing fees, hardware requirements, and maintenance costs associated with the database system.- Vendor support: Look for a reputable vendor that offers reliable technical support and regular updates for the database system.- Integration capabilities: Assess the compatibility and integration options with other systems and applications in the environment.6. The popular relational database management systems include:- Oracle Database: A widely used RDBMS known for its scalability, reliability, and advanced features.- MySQL: An open-source RDBMS suitable for small to medium-sized applications.- Microsoft SQL Server: A commercial RDBMS with excellent integration capabilities and comprehensive tooling.- PostgreSQL: An open-source RDBMS known for its robustness, extensibility, and support for advanced SQL features.7. Non-relational databases, also known as NoSQL databases, are an alternative to traditional relational databases. They are designed to handle large-scale data storage and processing requirements. Some popular types of NoSQL databases include:- Key-value stores: These databases store data in a key-value format for fast retrieval.- Document databases: These databases store and retrieve data in JSON-like documents.- Wide-column stores: These databases store data in tables with columns that can vary per row or record.- Graph databases: These databases are optimized for managing relationships between data elements.In conclusion, a relational database management system (RDBMS) is a powerful tool for organizing and managing data. When choosing a database system, it is important to consider factors such as data requirements, performance, scalability, availability, cost, vendor support, and integration capabilities. Popular RDBMS options include Oracle Database, MySQL, Microsoft SQL Server, and PostgreSQL. Additionally, NoSQL databases provide alternative solutions for specific data storage and processing needs.。

【CUUG 内部资料】OCP-12C-1Z0-062题库解析-第3次课序：2018年的时候，OCP 11g 考试题库大更新，052 053出现了很多新题，2019年，11g 即将停考的前期，Oracle 又出现了一次大变动，12c 出现了很多新题，比如062 063题库大更新QUESTION 31Which two are true concerning a multitenant container database with three pluggable database? A. All administration tasks must be done to a specific pluggable database. B. The pluggable databases increase patching time. C. The pluggable databases reduce administration effort. D. The pluggable databases are patched together . E. Pluggable databases are only used for database consolidation. Correct Answer: CEQUESTION 32Examine the current value for the following parameters in your database instance:SGA_MAX_SIZE = 1024M SGA_TARGET = 700M DB_8K_CACHE_SIZE = 124M LOG_BUFFER = 200M You issue the following command to increase the value of DB_8K_CACHE_SIZE:SQL> ALTER SYSTEM SET DB_8K_CACHE_SIZE=140M; Which statement is true? A. It fails because the DB_8K_CACHE_SIZE parameter cannot be changed dynamically. B. It succeeds only if memory is available from the autotuned components if SGA. C. It fails because an increase in DB_8K_CACHE_SIZE cannot be accommodated within SGA_TARGET .D. It fails because an increase in DB_8K_CACHE_SIZE cannot be accommodated withinSGA_MAX_SIZE. Correct Answer: B QUESTION 33Which three statements are true concerning unplugging a pluggable database (PDB)? A. The PDB must be open in read only mode. B. The PDB must be closed.C. The unplugged PDB becomes a non-CDB.D. The unplugged PDB can be plugged into the same multitenant container database (CDB)E. The unplugged PDB can be plugged into another CDB.F. The PDB data files are automatically removed from disk. Correct Answer: BDEC U U G C U U G C U U G 内部考试资料 内部考试资料 O C P 讨论群：1015267481C U U G C U U G C U U G 内部考试资料 内部考试资料 严禁外传O C P 讨论群：1015267481QUESTION 34Examine the following command:CREATE TABLE (prod_id number(4),Prod_name varchar2 (20), Category_id number(30), Quantity_on_hand number (3) INVISIBLE); Which three statements are true about using an invisible column in t he PRODUCTS table?A. The %ROWTYPE attribute declarations in PL/SQL to access a row will not display the invisible column in the output.B. The DESCRIBE commands in SQL *Plus will not display the invisible column in t he output.C. Referential integrity constraint cannot be set on t he invisible column.D. The invisible column cannot be made visible and can only be marked as unused.E. A primary key constraint can be added on t he invisible column. Correct Answer: ABE (解析：一般来说,看不见列帮助迁移和发展在线应用程序。

人工智能原理_北京大学中国大学mooc课后章节答案期末考试题库2023年1.Turing Test is designed to provide what kind of satisfactory operationaldefinition?图灵测试旨在给予哪一种令人满意的操作定义？答案:machine intelligence 机器智能2.Thinking the differences between agent functions and agent programs, selectcorrect statements from following ones.考虑智能体函数与智能体程序的差异，从下列陈述中选择正确的答案。

答案:An agent program implements an agent function.一个智能体程序实现一个智能体函数。

3.There are two main kinds of formulation for 8-queens problem. Which of thefollowing one is the formulation that starts with all 8 queens on the boardand moves them around?有两种8皇后问题的形式化方式。

“初始时8个皇后都放在棋盘上，然后再进行移动”属于哪一种形式化方式？答案:Complete-state formulation 全态形式化4.What kind of knowledge will be used to describe how a problem is solved?哪种知识可用于描述如何求解问题？答案:Procedural knowledge 过程性知识5.Which of the following is used to discover general facts from trainingexamples?下列中哪个用于训练样本中发现一般的事实？答案:Inductive learning 归纳学习6.Which statement best describes the task of “classification” in machinelearning?哪一个是机器学习中“分类”任务的正确描述？答案:To assign a category to each item. 为每个项目分配一个类别。

Oracle_11G_题库337ORACLE试题QUESTION NO: 1Identify two situations in which you can use Data Recovery Advisor for recovery. (Choose two.) 确定哪两种情况下，你可以使用用于恢复的数据恢复顾问。

A. The user has dropped an important table that needs to be recovered.B. The database files are corrupted when the database is open. 打开数据库时，数据库文件损坏。

C. You are not able to start up the database instance because the required database files are missing. 你不能启动数据库实例，因为所需的数据库文件丢失。

D. The archived log files are missing for which backup is not available. Answer: B,CQUESTION NO: 2Examine the following values of the initialization parameters in the database having the SID ORCL: 检查以下在数据库中具有ORCL SID的初始化参数的值：BACKGROUND_DUMP_DEST=/u01/app/oracle/product/11.1.0/db_1/bdumpUSER_DUMP_DEST=/u01/app/oracle/product/11.1.0/db_1/udumpCORE_DUMP_DEST=/u01/app/oracle/product/11.1.0/db_1/cdump DIAGNOSTIC_DEST= The environment variables have the following value: ORACLE_BASE=/u01/app/oracle ORACLE_HOME=/u01/app/oracle/product/11.1.0/db_1What is the location of the Automatic Diagnostic Repository (ADR) home? 自动诊断信息库（ADR）之家在什么位置？A. /u01/app/oracle/product/11.1.0/db_1B. /u01/app/oracleC.$ORACLE_HOME/bdump D. $ORACLE_HOME/log Answer: BQUESTION NO: 3Observe the following PL/SQL block: BEGINdbms_spm.configure('SPACE_BUDGET_PERCENT', 30); END;Which statement is correct regarding the above PL/SQL block? 有关上述PL / SQL块哪种说法是正确的？ A. It automatically purges the SQL management objects when SMB occupies more than 30% of the SYSAUX tablespace.B. It reserves 30% of the space in the SYSAUX tablespace for SQL Management Base (SMB).C. It reserves 30% of the space in the SYSTEM tablespace for SMB.D. It generates a weekly warning in the alert log file when SMB occupies more than 30% of the SYSAUX tablespace. 当SQL管理库占了30％以上的系统辅助表空间时，它会在警报日志文件中产生一个每周预警。

武汉理工大学大数据库系统原理总复习题(完整版含问题详解)理工高校数据库系统原理总复习题（完整版含答案）1. Questions1.1What is the purpose of a database?ANSWER：The purpose of a database is to help people track of things.1.2What is the most commonly used type of database?ANSWER: the most commonly used type of database is the relational database.1.7 Define the terms data and information. Explain how the two terms differ.ANSWER: Data are recorded facts and numbers.we can now define information as:●Knowledge derived from data.●Data presented in a meaningful context.●Data processed by summing, ordering, averaging, grouping, comparing orother similar operations.1.10 What problem can occur when a database is processed by more than one user?ANSWER: When more than one user employs a database application, these is always the chance that one user's work may interfere with other's.1.12 What is the purpose of the largest databases ate-commerce companies such as Amazon.?ANSWER: The largest databases are those that track customer browser behavior.（用来记录取户的扫瞄行为的。

Multiple-Choice Quiz 11.An E-Commerce system consists of the following components. Which of these same components must be included in a database? (c)The data, such as information about the goods available for sale, customers, orders placed, shipping information, etc.A database must include a collection of programs that control the data, such as programs to create, maintain, and manipulate the data. These programs can be easily used to create, maintain, and manipulate data in other domains.A database must include a collection of programs that operate on the data, but are specific to the E-commerce system. These programs enable users to browse through the store-items, place orders, track shipping, etc.(a) I, II, and III(b) I and II only(c) I only(d) II only2.An E-Commerce database contains data about customers, products, orders, system response times, etc. Which of the following can be specified as integrity constraints in an E-Commerce database system? (d)No two products can have the same product ID.The DBMS response time for all Web requests should be at most 2 seconds.A customer order cannot have more than one shipping address.(a) I only(b) I, II, and III(c) I and II only(d) I and III onlyFeedback: The constraints I, II and III specify the application semantics of the data captured in the E-Commerce database. Constraint III, although it seems contrary to common sense, is not something that can be prohibited by the DBMS because the DBMS is general purpose. The response time of the DBMS cannot be enforced by the DBMS. It depends on factors such the processor speed, memory available, etc.3. An E-Commerce system consists of the following components. Which of these same components will constitute a database system? (d)The data, such as information about the goods available for sale, customers, orders placed, shipping information, etc.A collection of programs that control the data, such as programs to create, maintain, and manipulate the data constitutes a database system. These programs can be easily used to create, maintain, and manipulate data in other domains such as in a library information system.A collection of programs that operate on the data, but are specific to the E-commerce system, constitutes a database system. These programs enable users to browse through the store-items, place orders, track shipping, etc.(a) I and II only(b) II only(c) I only(d) I, II, and IIIFeedback: A database system includes the data, the DBMS, and the application-specific programs that operate on that data.5. In a database system, whose responsibility is it to provide data consistency? (d)(a) the database administrator's(b) the user's(c) the application programmer's(d) the DBMS's6. A database is needed for which of the following application scenarios? (b)A video store that needs to keep track of data about members, about videos carried by the store, about videos rented by members, as well as data concerning borrow-date, return-date, and payment information.In the human resources department of a company, information about employees, their titles, their salaries and sick days, and about vacation days taken by each employee.A computer-simulated video game which needs to calculate and display, the physical (x, y) location of each actor in the game, the speed with which they are moving at the current instant, the direction in which they are moving, the action they are performing, the angle at which the game-player is viewing the scene.(a) I and III only(b) I and II only(c) I, II, and III(d) I only7.The physical storage structure will be _____ to the application programmer in a database approach, and will be _____ to the application programmer in a file system approach. (b)(a) visible, visible(b) hidden, visible(c) visible, hidden(d) hidden, hiddenMultiple-Choice Quiz 21. The foreign key in a table T1 _____ the same _____ as the corresponding primary key in table T2. (d)must have, nameneed not have, namemust have, domain(a) I, II, and III(b) I and II(c) I and III(d) II and III2. The degree of a table is the number of _____ in the table. (c)(a) keys(b) rows(c) columns(d) foreign keys3. The arity of a table is the number of _____ in the table. (c)(a) rows(b) foreign keys(c) columns(d) keys4. The cardinality of a table is the number of _____ in the table. (b)(a) keys(b) rows(c) columns(d) foreign keys5. Which of the following SQL statements can be used to add a row to a table? (c)(a) CREA TE(b) ADD(c) INSERT(d) APPEND6. The SQL clause to perform a set UNION operation is (b)(a) UNITE(b) UNION(c) COMBINE(d) MELD7. The SQL clause to perform a set difference operation is (b)(a) OMIT(b) EXCEPT(c) REJECT(d) DIFFER8. DDL is used to (c)(a) add contents to tables.(b) define the structure of database applications.(c) specify the structure of a database.(d) access the contents of tables.9. A deletion operation will _____ if the deletion leads to the violation of a referential integrity constraint. (a)(a) fail(b) crash the system(c) succeed with warning(d) succeed without warning10. The term query by example refers to (b)(a) a query for SQL examples(b) a visual query language developed by IBM(c) example SQL queries provided by other users that can be modified to suit current needs(d) example SQL queries provided by the DBMS that users can modify to suit their current needs11. What information is necessary when specifying the structure of a table? (d)(a) the name of the table and the amount of storage space to be allocated to the table(b) the name of the table and the names of the table's attributes(c) the name of the table, the names of the table's attributes, the data types of the table's attributes, the formats of the table's attributes, and the maximum number of rows that the table can have (d) the name of the table, the names of the table's attributes, the data types of attributes, and the formats of attributes12. What can be specified in the selection condition of a SELECT statement? (a)(a) a Boolean operation(b) the conditions under which the statement should be executed(c) the time at which the selection should be performed(d) an arithmetic operation13. Which of the following SQL statements can be used to modify just one row (out of many rows) in a table? (c)(a) ALTER(b) MODIFY(c) UPDA TE(d) CHANGE14. A deletion operation will _____ if the deletion leads to the violation of a referential integrity constraint. (c)(a) succeed with warning(b) succeed without warning(c) fail(d) crash the system15. Which of the following SQL statements can be used to create a relational table? (b)(a) APPEND(b) CREA TE(c) ADD(d) INSERT16. With Query By Example, a user enters a query by (b)(a) typing a syntactically correct SQL query that uses column and table names similar to the correct column and table names in a database(b) filling in skeleton tables of the database with examples of what is to be retrieved(c) placing SQL keywords, such as select, under the column names they want to retrieve(d) writing an English description of the data that the user needs17. DML is used to (d)(a) manipulate the structure of database applications.(b) specify the structure of a database.(c) add and delete tables.(d) add/modify/delete data in the database.18. A join operation joins _____ tables into _____. (a)(a) two, one(b) three, two(c) four, two(d) three, one//union/intersect/except参加运算的关系必须相容（即含有相同的属性集）19. A difference operation can be applied to tables that (b)(a) have the same column names(b) are union compatible(c) are the same size(d) have the same name20. Which of the following SQL statements can be used to remove a row from a table? (c)(a) REMOVE(b) ERASE(c) DELETE(d) DESTROYMultiple-Choice Quiz 31. In SQL, one function of the AS operator is to (c)(a) control the order in which a query’s rows are sorted(b) define the domain of an attribute(c) customize the names of columns in a query’s result(d) limit the cardinality of a relation2. When removing a table from the schema, using the RESTRICT option would (a)(a) remove the table if there are no references to it(b) remove the table and all other tables that the specified table refers to(c) remove the table and all references to it(d) recursively remove the table and all other tables that the removed table refers to3. In SQL, a database can be destroyed by which of the following? (a)(a) the command DROP SCHEMA(b) the command DELETE DA TABASE(c) the command DESTROY DA TABASE(d) a series of DESTROY TABLE commands4. When a string whose length is strictly less than n is entered as the value of a field whose SQL data type is V ARCHAR(n), the system responds by (b)(a) re-prompting for the entry of a string whose length is exactly n.(b) storing the string as is.(c) padding the end of the string with NULL characters to length n before storing it.(d) padding the end of the string with spaces to length n before storing it.5. In SQL, when destroying a database, the RESTRICT option removes (b)(a) everything in the specified database: the data, schema, etc.(b) the schema if the database has no data (empty tables)(c) the data and schema from the specified database, but not from related databases(d) the data but not the schema6. In SQL, a database can be created by which of the following? (d)(a) a series of CREA TE TABLE commands(b) the command ADD DA TABASE(c) the command INSERT DA TABASE(d) the command CREA TE SCHEMA7. In a FROM clause of a SELECT statement in SQL, a table can be aliased with which of the following operators? (b)(a) ALIAS(b) AS(c) RENAME(d) @8. In SQL, which of the following clauses can be used to sort results in ascending or descending order of attribute values? (c)(a) SORT(b) GROUP BY(c) ORDER BY(d) ARRANGE BY9. When specifying a selection criterion in SQL, attributes can be renamed with which of thefollowing operators? (d)(a) ALIAS(b) @(c) RENAME(d) AS10. In SQL, which of the following operators can be used to express searches that test for a range in a selection condition? (a)(a) BETWEEN(b) RANGE(c) START and END(d) FROM and TOMultiple-Choice Quiz 41. Which of the following is true about updateability of views? (a)(a) A view is updateable if it involves one table and contains a key.(b) A view is updateable if it involves multiple tables and no keys.(c) A view is updateable if it involves one table and does not contain a key.(d) A view is not updateable under any circumstance.2. A vertical view allows users access to (d)(a) only the system tables(b) only specific rows of the defining tables(c) only the user tables(d) only specific columns of the defining tables3. A horizontal view allows users access to (a)(a) only specific rows of the defining tables(b) only specific columns of the defining tables(c) only the system tables(d) only the base tables4. Consider two tables, Employee(EmpNo, Name, DeptNo) and Department(DeptNo, Name, Manager) with primary keys being EmpNo and DeptNo respectively. The DeptNo attribute of the Employee table has a NOT NULL constraint and is a foreign key that references the DeptNo attribute of the Department table. The Manager attribute of the Department table has a NOT NULL constraint and is a foreign key that references the EmpNo attribute of the Employee table. When the tables are empty, the only way to insert rows into the two tables is (d)(a) to use a transaction in NOT DEFERRABLE mode(b) to use a transaction either in DEFERRABLE mode or in NOT DEFERRABLE mode(c) not to use a transaction at all(d) to use a transaction in DEFERRABLE mode5. The SQL keyword _____ makes the modifications of the transaction permanent, while the SQL keyword _____ discards the modifications of the transaction. (b)(a) WRITE, ABORT(b) COMMIT, ROLLBACK(c) UPDA TE, SELECT(d) SA VE, CANCEL6. Which of the following commands can be used to give access permissions to a table? (a)(a) GRANT(b) AUTHORIZE(c) PERMIT(d) ALLOW7.Who can always give access permissions to a table? (b)(a) only the super-user(b) the owner of the table(c) the user of the table(d) only the database administrator (DBA)8. Which of the following commands can be used to remove access privileges associated with a table? (a)(a) REVOKE(b) DENY(c) RETRACT(d) REMOVE9. When is embedded SQL referred to as static SQL? (d)(a) when the SQL statements can never be changed(b) when the embedded SQL operates on the static part of the database(c) when the embedded SQL always returns the same set of results(d) when the embedded SQL is translated into DBMS calls at compile-time10. When is embedded SQL referred to as dynamic SQL? (a)(a) when the embedded SQL is translated into DBMS calls at run-time(b) when the embedded SQL operates on the dynamic part of the database(c) when the embedded SQL always returns different sets of results(d) when the SQL statements are changed in every run11. Which of the following is true about views being up to date? (a)(a) V iews are always up to date.(b) V iews can be automatically made up to date periodically by the system.(c) V iews are never up to date; there is always a lag time.(d) V iews are up to date only after the synchronization operation by the user.12. Which of the following referentially triggered actions are supported in SQL when a referential integrity constraint is violated? (a)SET NULLREJECTCASCADESET DEFAULT(a) I, III, and IV only(b) II and III only(c) I and IV only(d) I, II, and III only13. Which of the following is true about updateability of views? (c)(a) A view is not updateable if it involves one table and contains a key.(b) A view is updateable under all circumstances.(c) A view is not updateable if it involves aggregate functions and nested queries.(d) A view is not updateable under any circumstance.Multiple-Choice Quiz 51. In an ER model, what is a recursive relationship type? (d)(a) The type of relationship that does not belong anywhere(b) A never-ending type of relationship(c) The relationship type where the related entities are one and the same(d) The type of relationship between entities of one entity type2. In an ER model, the cardinality ratio of a relationship type is (b)(a) the number of instances of relationships of that relationship type(b) the number of relationships of that relationship type in which an entity can participate(c) the minimum number of entities that can participate in that relationship type(d) the number of entity types involved in that relationship type3. Which of the following is true about storage for derived attributes? (b)(a) Derived attributes must not be stored.(b) Derived attributes are usually not stored because they can be computed.(c) Derived attributes must be stored.(d) Derived attributes are usually stored because storage improves retrieval performance.4. A weak entity type implies a (c)(a) relationship with partial participation constraint(b) strong relationship type(c) relationship with total participation constraint(d) weak relationship type5.In the Entity-Relationship model, properties that characterize entities and relationships are modeled as (c)(a) weak entities(b) entity types(c) attributes(d) participation constraints6. In the Entity-Relationship model, a derived attribute is one (c)(a) that is composed of multiple atomic attributes(b) that may have multiple values simultaneously(c) whose value can be computed from the values of other attributes(d) that characterizes a relationship instead of an entity7. In an ER model, which of the following is true about a component attribute? (b)(a) A component attribute always contains other components.(b) A component attribute can be a composite attribute.(c) A component attribute is always atomic.(d) Component attributes must always be combined by an aggregation operation.8. In ER modeling, generalization is the process of generating (b)(a) entities out of attributes(b) superclasses out of subclasses(c) subclasses out of superclasses(d) attributes out of entities9. Which of the following is true about attributes in a relational model? (d)Attributes can be multi-valued.Attributes can be composite.(a) II only(b) Neither I nor II(c) I only(d) Both I and II10. When mapping from an ER model to a relational model, a strong entity is mapped into a (d)(a) row(b) column(c) key(d) table11. In the Entity-Relationship model, the degree of a relationship specifies which of the following?(d)(a) The cardinality ratio of the relationship(b) The number of attributes that characterize the relationship(c) The number of integrity constraints required to implement the relationship(d) The number of entities that participate in the relationship12. What is an identifying owner in an ER model? (b)(a) The entity upon which a strong entity's existence depends(b) The entity upon which a weak entity's existence depends(c) The relationship that identifies a strong entity's owner(d) The relationship that identifies a weak entity's ownerMultiple-Choice Quiz 61. Which of the following is a property (are properties) exhibited by good relational schemas? The use of null values in tuples (d)The grouping of as many attributes as possible into one main tableThe elimination of data redundancy to avoid update anomalies(a) II and III only(b) None(c) I and II only(d) III only2. Through normalization, update anomalies (c)(a) is usually left unchanged(b) can be minimized but not eliminated(c) can be eliminated(d) can be maximized3. Consider the following functional dependency.{A, B} -> {C}Regarding this dependency, which of the following statements is (are) true? (c)The values of C are uniquely determined by the values of A.The values of A are uniquely determined by the values of C.(a) I and II(b) I only(c) None(d) II only4. Which of the following problems can be caused by data redundancy in a relational schema? Inefficient use of space (a)Update anomalies and possible loss of dataInefficient use of processing time(a) I, II, and III(b) I and II only(c) II only(d) I and III only5. Through normalization, data redundancy (d)(a) can be minimized but not eliminated(b) are usually left unchanged(c) can be maximized(d) can be eliminated6. Consider a table with atomic attributes A, B, and C and the following functional dependencies.A -> BB -> CIf the primary key of this table is attribute A, then this relation satisfies which of the following normal forms? (c)FirstSecondThird(a) I, II and III(b) I only(c) I and II only(d) None7. For a relation to be in 3NF, it should not contain _____ attribute that is transitively dependent on _____. (a)(a) a non-primary key, the primary key(b) a primary key, a non-primary key(c) a primary key, a foreign key(d) a non-primary key, a foreign key8. The FD X -> Y is a full dependency in a relation R, if there is _____ attribute A that can be _____ X and the dependency still holds. (d)(a) at least one, removed from(b) at least one, added to(c) no, added to(d) no, removed from9. For a relation to be in 2NF, _____ attribute must be fully functionally dependent on _____. (b)(a) every alternate key, the primary key(b) every non-primary-key, the primary key(c) every non-key, at least one key(d) every non-key, every key10. The FD X -> Y is a partial dependency in a relation R, if there is _____ attribute A that can be _____ X and the dependency still holds. (c)(a) at least one, added to(b) no, removed from(c) at least one, removed from(d) no, added to11. Which of the following statements concerning normal forms is true? (b)(a) The lower the normal form number, the better the schema design is.(b) A relation that is in second normal form is also in first normal form.(c) Schemas that are in second normal form are considered the best.(d) Each normal form contains a state of independent properties, unrelated to other normal forms.Multiple-Choice Quiz 71. All changes made by a committed transaction can be recovered (d)(a) only if there have been no software failures(b) only if there have been no hardware failures(c) only if there have been no software AND no hardware failures(d) irrespective of whether there have been hardware or software failures2. Is it possible for a valid transaction to see the modified, yet uncommitted data of another valid transaction when the isolation level is set to SERIALIZABLE? (a)(a) It is not possible for a transaction to see the modified, yet uncommitted, data of another transaction, even if both transactions are working on the same data, and even if both transactions are concurrent.(b) It is possible for a transaction to see the modified, yet uncommitted, data of another transaction even if both transactions are not working on the same data, AND even if both transactions are NOT concurrent.(c) It is possible for a transaction to see the modified, yet uncommitted, data of another transaction only if both transactions work on the same data, AND both transactions are NOT concurrent.(d) It is possible for a transaction to see the modified, yet uncommitted, data of another transaction, only if both transactions work on the same data, AND both transactions are concurrent.3. A livelock occurs when (a)(a) a transaction is aborted and restarted repeatedly(b) a transaction holding a lock is aborted(c) 2 or more transactions wait indefinitely because each holds the data items of another(d) an aborted transaction holding a lock is restarted4. In a two-phase locking protocol, what happens during the growing phase? (d)(a) The transaction can acquire locks, and can release its locks.(b) The transaction cannot acquire locks, but can release its locks.(c) The transaction can acquire locks, and can release its locks as long as the number of acquired locks is greater than the number of released locks.(d) The transaction can acquire locks, but cannot release its locks.5. An exclusive lock on a data item represents permission to perform which of the operations, read and write, on the data item? (c)(a) Read only(b) Neither read nor write(c) Both read and write(d) Write only6. In a two-phase locking protocol, what happens during the shrinking phase? (a)(a) The transaction cannot acquire locks, but can release its locks.(b) The transaction can acquire locks, but cannot release its locks.(c) The transaction can acquire locks, and can release its locks.(d) The transaction can acquire locks, and can release its locks as long as the number of released locks is greater than the number of acquired locks.7. The strict two-phase locking protocol is _____ to implement. (c)(a) easier than most two-phase locking protocols(b) more difficult than most two-phase locking protocols(c) the easiest two-phase locking protocol(d) the most difficult two-phase locking protocol8. Force propagation policy _____ redo actions, and no-force propagation policy _____ redo actions. (a)(a) does not require, requires(b) requires, requires(c) requires, does not require(d) does not require, does not require9.Immediate update policy _____ undo actions, and deferred update policy _____ undo actions.(c)(a) does not require, requires(b) does not require, does not require(c) requires, does not require(d) requires, requires10. During recovery, in which of the following ways are the before and after images used by the undo and redo actions? (d)undo action uses the before imageundo action uses the after imageredo action uses the after imageredo action uses the before image(a) I, II, and III only(b) I, III, and IV only(c) I, II, III, and IV(d) I and III onlyMultiple-Choice Quiz 81. Which of the following are properties of a good hash function? (c)It should be computed efficiently.It should minimize the number of collisions by spreading keys as evenly and uniformly as possible.It should always use the Modulo (MOD) function.(a) I only(b) III only(c) I and II only(d) II only2. Where do heap files add new records? (c)(a) at random locations in the heap file(b) in the middle of the heap file(c) at the end of the heap file(d) at the beginning of the heap file3. Hashing exhibits the best performance for(a) range queries(b) ordering query results based on the key used for hashing(c) equality searches involving the key, provided the key is used for hashing(d) sequential scan of the entire table4. A sparse index contains entries for (a)(a) some records of a table(b) some fields of a table(c) all fields of a table(d) all records of a table5. A primary index _____ defined on a key field, and a secondary index _____ defined on a key field. (d)(a) need not be, should not be(b) should be, should not be(c) need not be, need not be(d) should be, need not be6. Each index entry in an index file contains (c)an indexing valuea pointer to the page where the record with the value appearsan indexing function(a) I only(b) I, II, and III(c) I and II only(d) III only7. A cylinder of a multi-platter hard disk consists of (b)(a) the outermost track(b) tracks with the same diameter(c) the innermost track(d) tracks with different diameters8. To improve the performance of a database, (d)(a) never use buffering when transferring data between secondary storage and main memory(b) never use hash files when deciding on an appropriate indexing structure(c) always use hash files when deciding on an appropriate indexing structure(d) minimize the amount of data transferred between secondary storage and main memory9. The term block transfer time refers to the amount of time it takes to (c)(a) load the address of a disk block from an index(b) move the read/write head to the appropriate track on the disk(c) read data from a disk(d) position the appropriate disk block under the read/write head10. The term blocking factor refers to the number of (c)(a) disk blocks that form a track(b) disk blocks that are on a hard disk drive platter(c) database records that can be stored on a disk block(d) cylinders on a hard disk drive11. How does chained overflow solve the problem of collisions in hashing? (d)(a) The first available empty bucket in a chained list of buckets is used.(b) The first available slot in the overflow area where slots are chained using a hash function is used.(c) The first available slot in a linked list of slots that is connected to the collision slot is used.(d) The first available slot in a linked list of overflow buckets that is connected to the hashed bucket is used.12. A secondary index is an index defined on a(n) _____ field. (a)(a) non-ordering(b) ordering(c) primary key(d) alternate key13. Which of the following can be used to measure hard disk drive performance? (b)Seek timeRotational latency。

整理过程参考了一末夕阳的博客，复习过程的心得是，一百题看完复习前一部分,同时我还整理了一份打印版本的，上面只有题目，没有答案，建议在电脑上先看答案整理那一份,没有答案的那份打印出来，复习使用，可以有效加强记忆。

1.While deploying a new application module, the software vendor ships the application software along with appropriate SQL plan baselines for the new SQLs being introduced。

Which two statements describe the consequences? (Choose two.)A。

The plan baselines can be evolved over time to produce better performance。

B. The newly generated plans are directly placed into the SQL plan baseline without being verified。

C。

The new SQL statements initially run with the plans that are known to produce good performance under standard test configuration.D. The optimizer does not generate new plans for the SQL statements for which the SQL plan baseline has been imported.当部署一个新的应用模块时，软件供应商与用于被引入的新SQL的适当的SQL计划基线一起运送应用软件。

哪两个语句描述了后果？A，计划基线可以随着时间的推移演变,产生更好的性能。