DATABASE ANALYSIS AND DESIGN (CISS-3330).03
"In an SQL SELECT command a SELECT clause with several attributes, a FROM clause with multiple tables and a WHERE clause with join fields set equal plus other predicates indicate a(n) ____.
"combination of relational Select, Project, and Join operations "
"All of the following are advantages of data and database administration, except ____."
"modularized, efficient programming "
"If the primary key of a table is clumsy because it has too many attributes and is replaced by a new, single attribute key, ____."
All of the above.
In the adding new tables physical database design technique ____.
All of the above.
"All of the following are SQL commands, except ____."
CREATE SELECT
"All of the following are responsibilities of data administration, except ____."
DBMS performance monitoring
Aggregation is a special case of the generalization/specialization relationship.
False
An instance of an object is an object class.
False
An object class can only be encapsulated if it is involved in an aggregation relationship.
False
An object/relational DBMS is an OODBMS with relational features added to them.
False
Clustering files disperses logically related data from two tables to different parts of the disk
False
Creating views actually changes the logical database design
False
The number of levels in a B+-tree index is permanently fixed at the time the file is created
False
In the SQL SELECT command, the attributes to be retrieved are specified in the ____ clause.
SELECT
The SQL SELECT built-in function that adds the values of a specified set of attributes is ____.
SUM
An object is an advanced data structure that includes an entity s attributes plus methods which can operate on and modify the object s attribute values.
True
Physical database design is the process of modifying the logical database design to improve performance.
True
Search arguments appear in the SQL SELECT command WHERE clause.
True
The DISTINCT operator in the SQL SELECT command removes duplicate rows from a query result.
True
Which of the following is a potential problem caused by adding too many indexes to a relational database?
Updating the indexes when the data is updated can slow down queries executing at the same time.
"In the SQL SELECT command, the search arguments that limit the rows involved in the query are specified in the ____ clause."
WHERE
In the SQL SELECT command, the search arguments that limit the rows involved in the query are specified in the ____ clause.
WHERE
The Entity-Relationship (E-R) model is _____.
a diagramming technique that describes entities, their attributes, and the relationships between them
A single piece of data is _____ the business environment.
a fact about
An object/relational DBMS is essentially ____.
a relational DBMS with object-oriented features
The SQL CREATE TABLE command is capable of doing all of the following, EXCEPT ____. a. building indexes b. specifying which attributes are unique c. specifying which attributes serve as the primary key d. specifying referential integrity constraints e. specifying which attributes serve as foreign keys
a. building indexes
An entity is _____ in the business environment.
an object or event
All of the following are SQL commands, EXCEPT ____. a. CREATE TABLE b. CREATE SELECT c. CREATE INDEX d. CREATE VIEW e. DROP TABLE
b. CREATE SELECT
All of the following are major DBMS approaches, EXCEPT _____. a. network b. index c. object-oriented d. relational e. hierarchical
b. index
In a merge-scan join ____.
both of the join attributes have to be in sorted order or have to have indexes built over them
In an automobile manufacturing company, an object about which we might want to maintain data could be any of the following, EXCEPT _____. a. an employee b. a finished car c. a length d. a supplier e. a sales meeting
c. a length
Converting a one-to-many binary relationship into a relational database from an E-R diagram ____.
can be done by placing the unique identifier of one of the tables into the other
Attributes in object classes in a generalization/specialization relationship ____.
can be inherited from the general class to the specialized classes
"In the object-oriented concept, abstract data types ____."
can have operations associated with them
In the object-oriented concept, abstract data types ____.
can have operations associated with them
"In a hashed file, synonym pointer chains _____."
can include only one record in the main storage area
In a hashed file, synonym pointer chains _____.
can include only one record in the main storage area
A dependent entity _____.
can only be present if the entity it depends on is present
In a magnetic disk device, a set of tracks, one above the other (and one from each recording surface) is called a _____.
cylinder
Having dedicated experts whose job it is to perform database design would be most directly characterized as ____.
efficiency in job specialization
The term for the relationship that recognizes that some kinds of entities can really be subdivided into smaller, more specific groups is ____.
generalization/specialization
The SQL SELECT GROUP BY clause is designed to ____.
group together the rows of a table that have a common attribute value
The navigational approaches to database management are _____.
hierarchical and network
The object classes in a generalization/specialization relationship are arranged in a ____.
hierarchy
"Consider Table A on the one side of a one-to-many relationship and Table B on the many side of the relationship. In the storing derived data physical database design technique, the best place to store the derived data from Table B is ____."
in a new column in Table A
An object ____.
includes an entity's attributes plus methods or operations which can operate on the attribute values
Each student at a university takes many courses; each course is taken by many students. The semester that a student took a course and the grade that the student received in the course is called _____ data.
intersection
A subquery can be used in place of a(n) ____.
join
Consider relations A and B. Relation A represents the entity on the "one side" of a one-to-many relationship; Relation B represents the entity on the "many side" of the one-to-many relationship. The delete rule between relations A and B is restrict. If an attempt is made to delete a record in relation A and its primary key value appears as a foreign key value in one or more records of relation B ____.
no records will be deleted
In terms of time, rotational delay in a disk device takes on average roughly _____.
one half of a revolution
Each building on a university campus has several faculty offices. Each professor has one office. The relationship between campus buildings and professors is a _____ relationship.
one-to-many binary
What is a description of a particular entity?
record occurrence
"In a magnetic disk device, the number of tracks in a cylinder is equal to the number of _____."
recording surfaces
In a magnetic disk device, the number of tracks in a cylinder is equal to the number of _____.
recording surfaces
The advantage of using the substituting foreign keys physical database design technique is that it is designed to ____.
reduce the number of joins
In the clustering files physical database design technique, ____ are clustered near each other on a disk.
related records from different tables
The DBMS approach in primary use today is _____.
relational
All of the following are steps in finding and transferring data from disk, except _____.
scan time
Data in ____ cannot have partial functional dependencies but can have transitive dependencies.
second normal form
Regarding the three data control issues of security, backup and recovery, and concurrency, a database management system _____.
should be responsible for handling all of them
A data definition language (DDL) ____.
specifies what tables will be in the database, what attributes will be in the tables, and which attributes will be indexed
Relational database management systems directly support ____.
tabular data such as accounting data
Which of the following is the correct order in which these magnetic storage technologies were introduced?
tape, drum, disk
Data integration is _____.
the ability to tie together pieces of related data in an information system
"In the division remainder hashing algorithm, the divisor (the number divided into the other number) is _____."
the number of main record storage locations (not including overflow locations)
In the division remainder hashing algorithm, the divisor (the number divided into the other number) is _____.
the number of main record storage locations (not including overflow locations)
In terms of performance, there is no point in indexing a table if ____.
the number of rows of the table is very small
The starting point of the physical database design process is ____.
the output of the logical database design process
A relational query optimizer optimizes ____.
the performance of a relational query
"All of the following are factors affecting application and database performance, except ____."
the presence of primary keys
Consider relations A and B. Relation A represents the entity on the "one side" of a one-to-many relationship; Relation B represents the entity on the "many side" of the one-to-many relationship. The delete rule between relations A and B is cascade. If an attempt is made to delete a record in relation A and its primary key value appears as a foreign key value in one or more records of relation B ____.
the record in relation A and all of the records in relation B with foreign key values that match the primary key value of the record in relation A will be deleted
Using the division remainder algorithm for a hashed file _____.
the record insertion location is based on the division s remainder
Using the division remainder algorithm for a hashed file _____.
the record insertion location is based on the division's remainder
Data in ____ cannot have transitive dependencies.
third normal form
The SQL SELECT BETWEEN operator is used ____.
to find a numeric value between two numeric values
The purpose of the SQL SELECT GROUP BY clause is ____.
to group together rows of a table with common attribute values in order to perform calculations using the built-in functions on attributes within each group
"In a magnetic disk device, a single circle of stored data is called a _____."
track
The SQL SELECT command is capable of executing ____.
"relational Select, Project, and Join operations individually or in combination "
The common advantage of separating portions of a table s data using either horizontal or vertical partitioning is that ____.
"the data in a partition can be stored in a concentrated space on the disk, which will speed up its retrieval "
A data manipulation language (DML) is capable of ____.
1. inserting new records or rows into a relation 2. deleting records or rows of a relation 3. retrieving data from a relation
Structured Query Language (SQL) ____.
1. is capable of retrieving data from a relational database 2. is capable of defining the tables, attributes, and indexes of a relational database
How many entities are described in the Course file?
5 entities
Typing SQL SELECT commands in at a keyboard and sending them directly to the relational DBMS for processing is referred to as ____.
: query mode
What is true regarding indexed sequential files and B+-trees?
A B+-tree indexed file is an indexed sequential file.
"All of the following are responsibilities of database administration, except ____."
Data planning
What is true about data redundancy within one file?
Data redundancy within one file occurs when different kinds of data (data about different entities) are merged in one file.
In the SQL SELECT command, the table(s) involved in the query is (are) specified in the ____ clause.
FROM
"In a generalization/specialization hierarchy, attributes can be inherited downwards from the general object class to the specialized object classes, but methods or operations cannot."
False
"In the SQL SELECT command embedded mode, the user types the command at a workstation and presses the Enter key. The command goes directly to the relational DBMS, which evaluates the query and processes it against the database. "
False
"In the division remainder hashing algorithm, the divisor (the number divided into the key value) is the total number of record storage locations in the main storage area plus the overflow area."
False
"In the physical design technique known as substituting foreign keys , the table with the foreign key in it has its primary and foreign keys interchanged."
False
"The OR operator in the SQL SELECT command WHERE clause means one or the other, but not both."
False
"The more volatile the data in a table, the less will be the negative performance effect of having a relatively large number of indexes built over it."
False
"The relational data model does not directly support such data types as photo images, video clips, and audio clips."
False
"The three ways of achieving direct access are with an index, with a tape drive, and with a hashing method.
False
"The three ways of achieving direct access are with an index, with a tape drive, and with a hashing method."
False
"Transfer time is the time it takes to actually move the data from the disk to primary memory before the seek, head switching, and rotational delay operations take place."
False
"When tables are to be joined in an SQL SELECT statement, the join attributes from each table are set equal to each other in the FROM clause."
False
A BLOB (binary large object) is an example of generalization/specialization hierarchy.
False
A GROUP BY clause in an SQL SELECT command groups together columns based on common attribute values.
False
Data administration typically carries out many of the policies set by database administration.
False
Generalization/specialization is a relationship in which a class is shown to be composed of other classes.
False
If several AND and OR operators appear in an SQL SELECT command WHERE clause and they are not separated by parentheses, all of the OR operations will be performed before any of the AND operations."
False
One of the main advantages of a hashed file is that it never has to be reorganized.
False
Only two tables can be joined in an SQL SELECT statement.
False
Primary keys are good candidates for being indexed but foreign keys are not.
False
Response time is the measure of how many queries from simultaneous users must be satisfied in a given period of time by the application set and the database that supports it.
False
The BETWEEN operator in the SQL SELECT command WHERE clause requires that a character string must be between two specified character strings.
False
The volume of data in the database does not enter into database performance.
False
The forerunner of the annual report was the Code of Commerce, which was instituted in 1673 in _____.
France
A relational query optimizer ____.
None of the above
The SQL SELECT ORDER BY operator ____.
None of the above.
What is a basic principle of the database concept?
The ability to achieve data integration without introducing redundant data.
The cardinality of a relationship is _____.
The maximum number of entities that can be involved in the relationship.
The modality of a relationship is _____.
The minimum number of entities that can be involved in the relationship.
"If a file is hashed on one field, direct access based on another field can be achieved by building an index on the other field."
True
"In a hashed file, a collision occurs when the key values of two records hash to the same record storage location. "
True
"In a hashed file, a collision occurs when the key values of two records turn out to be synonyms."
True
"In a relational DBMS, the main purpose of the relational catalog is to accurately support the relational query optimizer."
True
"In an indexed-sequential file, an index is built over the same field on which the file is sequenced."
True
"In the B+-tree index arrangement described in the text, the lowest level of the index tree is stored using a track in each data cylinder."
True
"Once a GROUP BY clause in an SQL SELECT command groups together rows based on common attribute values, a built-in function can produce a result for each group."
True
"When a new record is inserted into a file, an existing record is deleted, or an indexed field is updated, all of the affected indexes must be updated."
True
A basic SQL SELECT command is capable of performing a combination of relational Select and Project operations.
True
A data repository is a large-scale data dictionary with advanced entity types
True
A file with a B+-tree index is an indexed-sequential file.
True
A record is inserted into a location in a hashed file based on the result of a hashing algorithm applied to the record s key value.
True
A relational query optimizer is an expert system within a relational DBMS.
True
A view is an important device in protecting the security and privacy of data.
True
Adding duplicate tables to a database reduces access bottlenecks and has no negative effects.
True
Aggregation is denoted by a diamond-shaped symbol in a UML diagram.
True
Among the responsibilities of data administration are data coordination and data planning.
True
Among the responsibilities of database administration is the physical design of shared databases.
True
An OODBMS allows associated operations to be defined along with abstract data types
True
An object/relational database might include a table that has audio clip data in one of its columns.
True
Denormalization improves the performance of join operations at the expense of reintroducing data redundancy.
True
Generalization/specialization relationships are a form of aggregation relationships
True
Modifying the logical database design to improve performance may reintroduce data redundancy.
True
One of the reasons for having secondary memory is that primary memory cannot possibly hold all of a company s programs and data.
True
One of the reasons for having secondary memory is that primary memory cannot possibly hold all of a companys programs and data
True
The Unified Modeling Language (UML) is the standard diagramming notation for object-oriented systems development.
True
The first step in indexing a file using a simple linear index is to copy a set of field values from the file into the index and to sort them.
True
The physical design technique known as substituting foreign keys can improve performance by avoiding joins in certain situations.
True
The tables used in a SELECT command are listed in the FROM clause.
True
The use of a subquery in an SQL SELECT statement is always optional.
True
The way that data is stored for subsequent retrieval is known as its file organization.
True
When an application program has to update encapsulated data, it sends a message to one of the object s encapsulated operations to trigger the operation."
True
Which of the following is true? a. Data integration is desirable but data redundancy is not. b. Data redundancy is desirable but data integration is not. c. Both data integration and data redundancy are desirable. d. Neither data integration nor data redundancy is desirable. e. None of the above.
a. Data integration is desirable but data redundancy is not.
Each of the following is one of the fundamental operations that can be performed on stored data, EXCEPT _____. a. converge b. retrieve c. insert d. delete e. update
a. converge
All of the following are true about data redundancy across multiple files, EXCEPT _____. a. it speeds updates when the redundant data must be updated b. it is a managerial problem when the company does not encourage data sharing c. it is a technical problem when the company's software systems do not support data sharing d. it wastes disk space e. it can potentially cause data integrity problems
a. it speeds updates when the redundant data must be updated
All of the following are basic principles of the database concept, EXCEPT _____. a. maintaining redundant data that does not cause data integrity problems b. the ability to store data in a non-redundant fashion c. the ability to store data representing entities involved in multiple relationships d. striving to achieve a high degree of data independence e. data integration
a. maintaining redundant data that does not cause data integrity problems
All of the following kinds of data are candidates for abstract data types, EXCEPT ____. a. numeric data b. video clips c. audio clips d. photo images e. graphic images
a. numeric data
Which of the following does NOT change the contents of a file? a. retrieve b. insert c. delete d. update e. all of the above
a. retrieve
All of the following are challenges to the efficient storage and access of data, EXCEPT _____. a. the data type b. the data volume c. the number of people who want access to the data d. data security e. data privacy
a. the data type
A plan for the steps to take to respond to a relational query is called a(n) ____.
access path
The term for the relationship in which a class is shown to be composed of other classes is ____.
aggregation
Rebuilding a database after it is destroyed by a natural disaster is an aspect of _____.
backup and recovery
In a generalization/specialization relationship ____.
both attributes and operations can be inherited
All of the following were early forms of record keeping associated with the rise of cities, EXCEPT _____. a. marriage records b. family trees c. annual reports d. calendars e. church contribution records
c. annual reports
All of the following features of a relational query or of the relational database that it accesses are considered by the relational query optimizer, EXCEPT ____. a. whether a search argument in the query is a unique attribute in the database b. whether a search argument in the query involves an indexed attribute c. the number of rows of output the query produces d. the number of rows of the database tables involved e. whether a join attribute in the query involves an indexed attribute
c. the number of rows of output the query produces
The SQL SELECT HAVING clause limits the output of a GROUP BY operation based on ____.
calculated values of the built-in functions
Consider Table A on the one side of a one-to-many relationship and Table B on the many side of the relationship. The primary key of Table A has been placed in Table B as a foreign key. The substituting foreign keys physical database design technique ____.
can only be performed if Table A has more than one candidate key
When different kinds of data (data about different entities) are merged in one file, a deletion anomaly _____.
causes a loss of data that may not be stored anywhere else
An attribute is a _____.
characteristic of an entity
The objects that describe similar entities are known collectively as a(n) ____.
class
An entity set is a _____.
collection of entities of the same type
In an SQL SELECT command a SELECT clause with several attributes, a FROM clause with multiple tables and a WHERE clause with join fields set equal plus other predicates indicate a(n) ____.
combination of relational Select, Project, and Join operations
Consider Table A on the "one side" of a one-to-many relationship and Table B on the "many side" of the relationship. Denormalization ____.
combines the data in the two tables into one table
Protecting against hackers is primarily a matter of _____.
computer security
Problems caused by two or more users trying to update the same data simultaneously fall primarily under the heading of _____.
concurrency control
Prior to the development of the database concept, redundant data ____.
could be found within individual files and across multiple files
All of the following are terms associated with magnetic disk technology, EXCEPT _____. a. fixed b. removable c. non-removable d. punched e. multi-platter
d. punched
When data structures can be modified without affecting the programs that use the data, we say that the environment is highly _____.
data independent
The frequency with which stored data is updated is known as ____.
data volatility
Prior to the development of the database concept ____.
data was not regularly shared among applications
The software that was developed to handle the increasing volumes of data and treat it as a corporate resource is called a(n) _____.
database management system
When different kinds of data (data about different entities) are merged in one file, what anomalies can occur?
deletion, insertion, and update
Intersection data _____.
describes the relationship between two entities in a many-to-many relationship
Retrieving a single record of a file based on a field value is an example of _____.
direct retrieval
Retrieving a subset of the records of a file based on a field value is an example of _____.
direct retrieval
Informing potential users of what data already exists in the database would be most directly characterized as ____.
documentation and publicity
A relational query optimizer ____. a. is a form of a relational catalog b. is a separate piece of software that can be added to the relational DBMS environment as an option c. can be invoked at the option of the user issuing the query d. is only used with queries involving joins e. None of the above.
e. None of the above.
Data redundancy _____. a. can occur across multiple files but not within a single file b. can occur within a single file but not across multiple files c. is a positive feature in the simple linear file environment but is a negative feature in the database environment d. is a negative feature in the simple linear file environment but is a positive feature in the database environment e. None of the above.
e. None of the above.
In a relational database, a logical view ____. a. is a physical duplicate of part of a table b. is a physical duplicate of all of a table c. is created with the SQL CREATE TABLE command d. must be built over a single table, i.e. it cannot involve joined tables e. None of the above.
e. None of the above.
The SQL SELECT ORDER BY operator ____. a. groups together rows with identical values of a specified attribute b. groups together columns with identical values of a specified attribute c. changes the order of the rows of one of the tables in a Join operation d. changes the order of the columns of one of the tables in a Join operation e. None of the above.
e. None of the above.
The SQL SELECT built-in function COUNT ____. a. adds the values of a specified set of attributes b. adds the values of the numeric attributes in a row of the output of an SQL SELECT command c. counts the number of columns in the output of an SQL SELECT command d. counts the number of columns in the table resulting from a Join operation e. None of the above.
e. None of the above.
Depending on the attributes and circumstances present, the unique identifier of an associative entity could be any of the following, EXCEPT _____. a. the combination of the unique identifiers of the entities in the many-to-many relationship consisting of exactly one field from each entity b. the combination of the unique identifiers of the entities in the many-to-many relationship consisting of several fields c. the combination of the unique identifiers of the entities in the many-to-many relationship plus one or more additional fields that express times or dates d. a single field that is associated with the associative entity and provides unique values e. a unique combination of fields from one of the two entities in the many-to-many relationship
e. a unique combination of fields from one of the two entities in the many-to-many relationship
All of the following are corporate resources, EXCEPT _____. a. money b. inventory c. data d. plant and equipment e. competitors
e. competitors
All of the following are kinds of corporate resources, EXCEPT _____. a. data b. capital c. inventory d. plant and equipment e. competitors
e. competitors
All of the following were types of electro-mechanical, punched card based devices, EXCEPT _____. a. calculators b. collators c. punches d. sorters e. disk drives
e. disk drives
All of the following are true about the use of AND and OR operators in an SQL SELECT command, EXCEPT ____. a. AND has higher precedence than OR b. AND and OR can be used together with any of the comparison operators c. OR means one condition or the other or both d. enclosing an AND or an OR operation in parentheses ensures that it will be performed before those outside of parentheses e. either the AND or the OR operator may be used in a given SQL SELECT command, but not both
e. either the AND or the OR operator may be used in a given SQL SELECT command, but not both
All of the following are true about encapsulation, EXCEPT____. a. it is designed to improve data integrity b. it prevents application code outside of the encapsulated object from modifying the object's data c. a message from an application program can trigger an encapsulated object d. operations are stored in the database together with the data they operate on e. objects can only be encapsulated if they are in an aggregation relationship
e. objects can only be encapsulated if they are in an aggregation relationship
All of the following are true regarding a join operation in an SQL SELECT command, EXCEPT ____. a. it requires at least two tables to be specified in the FROM clause b. it can involve the specification of more than two tables in the FROM clause c. it requires corresponding join attributes to be set equal to each other in the WHERE clause d. it can also involve relational Select and Project operations in the same SQL SELECT command e. there will be at least two tables in the query output because at least two tables were involved in the join
e. there will be at least two tables in the query output because at least two tables were involved in the join
The SQL SELECT DISTINCT operator ____.
eliminates duplicate rows in the output of an SQL SELECT command
Placing SQL SELECT commands among the lines of a higher-level language program if referred to as ____.
embedded
A binary relationship is a relationship between two _____.
entity types
In the Course file, the string "Anatomy" can best be described as a _____.
field occurrence
Which of the following is a collection of descriptions of the entities in an entity set?
file
Data in ____ has only a single attribute value in every attribute position.
first normal form, second normal form, and third normal form
An one-to-one unary relationship _____.
involves a single entity type
The SQL SELECT IN operator ____.
involves looking for character strings and can be used instead of a series of OR operators
The SQL SELECT LIKE operator ____.
involves the use of wildcards
A one-to-one binary relationship _____.
involves two entity types
Which of the following is the unique identifier of an entity?
key
Optical disk technology is based on _____.
lasers
Retrieving the records of a file in order based on a set of field values is referred to as _____.
logical sequential retrieval
A subset of the columns and/or rows of a table is called a ____.
logical view
An associative entity is an alternate way of expressing a(n) _____.
many-to-many binary relationship
The data processing equipment that Herman Hollerith developed for the 1890 U.S. census is classified as electro- _____ equipment.
mechanical
The term that describes data about data is ____.
metadata
A many-to-many binary relationship allows an occurrence of one entity type to be associated with _____.
multiple occurrences of another entity type
An one-to-many binary relationship allows an occurrence of the entity type on the "one side" of the relationship to be associated with _____.
multiple occurrences of the entity type on the "many side" of the relationship
A many-to-many unary relationship allows an occurrence of one entity type to be associated with _____.
multiple occurrences of the same entity type
An one-to-many unary relationship allows an occurrence of the entity type on the "one side" of the relationship to be associated with _____.
multiple occurrences of the same entity type
A ternary relationship allows an occurrence of one entity type to be associated with _____.
multiple occurrences of two other entity types
In a university setting, the relationship between students and the professors who have been their instructors is a _____ relationship.
one-to-many binary
In a university, the relationship between courses and their sections can best be described as a _____ relationship.
one-to-many binary
In a university setting, every professor reports to another professor who is the department chair. This is a _____ relationship.
one-to-many unary
A business school's faculty parking lot has assigned parking spaces. Each professor is entitled to one parking space. This is an example of a _____ relationship.
one-to-one binary
In a university setting, each student is paired with another student for the purpose of getting assignments and turning in work for the other if he is out of school for any reason. This is a _____ relationship.
one-to-one unary
The term that describes a non-key field of a relational table being dependent on only part of the table's key is ____.
partial functional dependency
Denormalization can improve the ____.
performance of the database by reducing the number of join operations
By definition, a database management system _____.
permits data to be stored non-redundantly and provides for data integration
Retrieving the records of a file in order based on the order in which they are stored on a disk is referred to as _____.
physical sequential retrieval
The modification or refinement of operations as they are inherited downwards in a generalization/specialization relationship is called ____.
polymorphism
Data normalization ____.
precedes physical database design
A logical view is an important device in ____.
protecting the security of the data
In 1805, Jacquard invented _____ as a data storage medium for storing patterns to be woven into cloth.
punched cards
The data processing equipment that Herman Hollerith developed for the 1890 U.S. census used _____ as a data storage medium.
punched cards
The earliest (1870s) form of modern data storage was _____.
punched paper tape
Typing SQL SELECT commands in at a keyboard and sending them directly to the relational DBMS for processing is referred to as ____.
query mode
In the Course file, the string "ENGL2540 Shakespeare 3 Duncan" can best be described as a _____.
record occurrence
"In an SQL SELECT command, a SELECT clause with several attributes and the absence of a WHERE clause indicates a(n) ____."
relational Project operation
In an SQL SELECT command, a SELECT clause with several attributes and the absence of a WHERE clause indicates a(n) ____.
relational Project operation
The SQL SELECT command is capable of executing ____.
relational Select, Project, and Join operations individually or in combination
An association between entities is a(n) _____.
relationship
The creating a new primary key physical database design technique is designed to ____
replace clumsy keys that have a large number of attributes
The creating a new primary key physical database design technique is designed to ____.
replace clumsy keys that have a large number of attributes
Representing a unary one-to-many relationship in a relational database ____.
requires adding a new column, the domain of values of which is the same as the relation's primary key
The SQL SELECT command is used to ____ a relational database.
retrieve data from
A university wants to keep track of which professor taught which subject to which student. This is a _____ relationship.
ternary
Unified Modeling Language (UML) is ____.
the standard diagramming notation for object-oriented systems development
When an SQL SELECT command has a subquery within it ____.
the subquery is executed first
"All of the following are true about secondary memory devices, except _____."
they are volatile
"All of the following are characteristics of relational DBMS catalogs, except ____."
they include the full range of data dictionary entities
The Crusades eventually led to an increased interest in record keeping because _____.
they introduced Europeans to the possibilities of expanded trade
In a magnetic disk device, a single circle of stored data is called a _____.
track
The term "binary" in binary relationship indicates that the relationship is between ________.
two entity types
The Bill of Materials problem is an example of a ____.
unary many-to-many relationship
A database management system is designed to handle _____ relationships without introducing data redundancy or causing other problems.
unary, binary, and ternary
Double-entry bookkeeping _____.
was an outgrowth of trading partnerships
Direct access can be achieved _____.
with either an index or a hashing method
All of the following are factors affecting application and database performance, EXCEPT ____. a. the length of attribute names b. large data volumes c. the number of data access operations d. the need for joins e. related data dispersed on the disk
a. the length of attribute names
The term that describes an attribute whose value establishes the value of another attribute is ____.
determinant
Vertical partitioning ____.
- means dividing the columns of a table into groups and storing the groups separately, on different areas of a disk or on different disks - may involve splitting large text attributes off from the rest of a table
A relational table in third normal form ____.
-is also in first normal form, -is also in second normal form, and -has no transitive dependencies
Data normalization ____.
-is capable of creating relational tables that are free of data redundancy, -is a logical database design technique, and -can be used to check the accuracy of the E-R diagrams to relational tables conversion technique
What is true about indexes, in general?
An index can be used to retrieve the records of a file in logical sequence based on the indexed field.
The most common data indexing system in use today is the _____.
B+-tree index
What are logical database design techniques?
Conversion of E-R diagrams to relational tables and Data normalization.
An example of an active data dictionary s use in the input sense is if it must be consulted to see who is authorized to access particular data
False
Taking application priorities into account in physical database design is important because ____.
a modification to a table that's designed to help the performance of one application may hinder the performance of another application
Programs and data are loaded into primary memory from secondary memory when they are required for processing
True
What is a potential problem caused by adding too many indexes to a relational database?
Updating the indexes when the data is updated can slow down queries executing at the same time.
In a hashed file using the division remainder method _____.
a collision results from the key values of two records having the same remainder in the hashing calculation
All of the following are characteristics of an indexed computer file and its index, EXCEPT _____. a. the records of the file are sorted into the same order as the values in the index b. a set of field values is copied from the file into the index c. the field values copied into the index are sorted in the index d. the field values in the index are associated with the location of the records in the file from which they were copied e. the index consists of two columns, one for the field values copied from the file and one for the pointers back to the records of the file.
a. the records of the file are sorted into the same order as the values in the index
All of the following are advantages of the B+-tree index arrangement, compared to the simple linear index arrangement, EXCEPT _____. a. The upper portion of the tree index can be held in main memory indefinitely to improve performance. b. The insertion of a new record requires either a track split or a cylinder split, but not both for a single insertion. c. Even for large files, only a small number of index records have to be read for a direct search. d. The nature of the index together with the track split and cylinder split capabilities make record insertions manageable. e. Some insertions can be made without track splits or cylinder splits if reserve space has been provided on the data tracks.
b. The insertion of a new record requires either a track split or a cylinder split, but not both for a single insertion.
All of the following are true about B+-tree indexes and their files, EXCEPT _____. a. The records of the file are stored in order by key value. b. Both a number of tracks and a number of cylinders are held empty in reserve for new record insertion purposes. c. Every insertion of a new record requires the use of an empty reserve track or cylinder. d. It is possible that a new record insertion can increase the number of levels of the index tree. e. The lowest level of the index is stored on the same cylinders as the data.
c. Every insertion of a new record requires the use of an empty reserve track or cylinder.
Hashed files _____.
can also have indexes built over them
Converting a many-to-many unary relationship into a relational database from an E-R diagram ____.
can be done by adding another copy of the unique identifier of the single entity's table into the same table with a different attribute name
Converting a one-to-many unary relationship into a relational database from an E-R diagram ____.
can be done by adding another copy of the unique identifier of the single entity's table into the same table with a different attribute name
Converting a one-to-one unary relationship into a relational database from an E-R diagram ____.
can be done by adding another copy of the unique identifier of the single entity's table into the same table with a different attribute name
Converting a one-to-one binary relationship into a relational database from an E-R diagram ____.
can be done by placing the unique identifier of one of the tables into the other OR by creating a single table that combines the attributes of the two entities
Consider Table A on the "one side" of a one-to-many relationship and Table B on the "many side" of the relationship. The primary key of Table A has been placed in Table B as a foreign key. The substituting foreign keys physical database design technique ____.
can only be performed if Table A has more than one candidate key
All of the following are inputs into the physical database design process, EXCEPT ____. a. application data requirements b. throughput requirements c. hardware characteristics d. functional dependencies e. application priorities
d. functional dependencies
Placing the unique identifier of one database table in another existing or new table in the database ____.
creates a foreign key, may indicate the creation of a one-to-many binary relationship, and may indicate the creation of a many-to-many binary relationship
All of the following are good candidates for having an index built over them, EXCEPT ____. a. foreign key b. search attribute c. primary key d. All of the above. e. None of the above.
d. All of the above.
Application data requirements that enter into the physical database design process include ____. a. the number of applications that will share particular database tables b. the frequency with which applications that utilize particular tables are run c. whether or not particular applications require that tables be joined d. All of the above.
d. All of the above.
If the primary key of a table is clumsy because it has too many attributes and is replaced by a new, single attribute key, ____. a. it becomes the new primary key of its own table b. it should replace the old primary key where it was used as a foreign key for one-to-many relationships c. it should replace the old primary key where it was used as a foreign key for many-to-many relationships d. All of the above. e. None of the above.
d. All of the above.
In the adding new tables physical database design technique ____. a. subsets of the most heavily accessed portions of existing tables can be copied and created as new tables b. entire tables can be copied and new tables created c. data redundancy across tables is traded-off against improved performance d. All of the above. e. None of the above.
d. All of the above.
Which of the following is true regarding hashed files? a. The hashing algorithm may direct more than one record to the same location. b. The number of record storage locations allocated is typically much fewer than the maximum number possible based on the range of values of the key field. c. The same hashing algorithm is used for both record insertions and record retrievals. d. All of the above.
d. All of the above.
Which of the following regarding checking the results of one logical database design technique with another is TRUE? a. Neither the E-R diagram conversion process result nor the data normalization result can be checked with the other process. b. The E-R diagram conversion process result and the data normalization result can each be checked with the other process. c. The result of data normalization is checked with the E-R diagram conversion process. d. The result of the E-R diagram conversion process is checked with data normalization. e. None of the above.
d. The result of the E-R diagram conversion process is checked with data normalization.
All of the following are true about B+-tree indexes and their files, EXCEPT _____. a. A file with a B+-tree index built over the field by which the file is stored in sequence is an indexed sequential file. b. A track split might lead to a cylinder split. c. A track split might not lead to a cylinder split. d. A cylinder split must lead to a change in the tree index. e. A cylinder split must lead to an increase in the number of levels of the index tree.
e. A cylinder split must lead to an increase in the number of levels of the index tree.
Referential integrity ____. a. is ONLY an issue in the relational database approach b. is NOT an issue in the relational database approach c. involves individual relations in isolation d. ONLY involves relations that contain redundant data e. None of the above
e. None of the above
A relational table in first normal form ____. a. is also in second normal form b. is also in third normal form c. has no transitive dependencies d. has no determinants e. None of the above.
e. None of the above.
A ternary relationship ____. a. CANNOT have intersection data associated with it b. stores its intersection data in the three relations created to represent the three binary many-to-many relationships that form the ternary relationship c. stores its intersection data in the three relations that represent the three entity types in the ternary relationship d. stores its intersection data in one of the three relations that represent the three entity types in the ternary relationship e. None of the above.
e. None of the above.
A ternary relationship is the equivalent of ____ binary many-to-many relationship(s). a. one b. two c. three d. four e. None of the above.
e. None of the above.
Logical database design ____. a. is a part of physical database design b. includes physical database design as one of its elements c. results in a set of database tables that contain redundant data d. results in a set of database tables that are optimized for performance e. None of the above.
e. None of the above.
The storing derived data physical database design technique is designed to ____. a. reduce the number of joins b. reduce the number of indexes c. replace clumsy keys that have a large number of attributes d. All of the above. e. None of the above.
e. None of the above.
All of the following are factors affecting application and database performance, EXCEPT ____. a. overly liberal data access b. the need to calculate totals c. clumsy primary keys d. the lack of direct access e. the presence of primary keys
e. the presence of primary keys
All of the following are true about secondary memory devices, EXCEPT _____. a. they include magnetic disk b. they are necessary because primary memory cannot hold all of a company's data and programs c. they are non-volatile d. data and programs are loaded from secondary memory into primary memory for processing e. they are volatile
e. they are volatile
In third normal form, the exception to the rule that a non-key attribute cannot define another non-key attribute is ____.
if the defining attribute is a candidate key
Consider Table A on the "one side" of a one-to-many relationship and Table B on the "many side" of the relationship. In the storing derived data physical database design technique, the best place to store the derived data from Table B is ____.
in a new column in Table A
Referential integrity is an issue in record ____.
insertion, deletion, and update
The drawback of denormalization is that it ____.
introduces data redundancy
In the diagram, the Course file and its index _____.
is NOT an indexed sequential file because the indexed field is not the one on which the file is sequenced
A relational table in second normal form ____.
is also in third normal form
The clustering files physical database design technique ____.
is designed to improve the performance of a join operation
Combining two tables that represent a one-to-one relationship ____.
is designed to reduce the number of joins in the database environment
Horizontal partitioning ____.
means dividing the rows of a table into groups and storing the groups separately, on different areas of a disk or on different disks
Representing a ternary relationship in a relational database ____.
requires the creation of an additional relation
Representing a unary many-to-many relationship in a relational database ____.
requires the creation of an additional relation
Converting a ternary relationship into a relational database from an E-R diagram ____.
requires the creation of an additional table beyond the three that represent the three entities in the relationship
Converting a many-to-many binary relationship into a relational database from an E-R diagram ____.
requires the creation of an additional table beyond the two that represent the two entities in the relationship
The delay from the time that the Enter Key is pressed to execute a query until the result appears on the screen is called ____.
response time
In the diagram, for the Course file and its index, ___________.
the Course Name field in the index must be in sorted order.
The common advantage of separating portions of a table's data using either horizontal or vertical partitioning is that ____.
the data in a partition can be stored in a concentrated space on the disk, which will speed up its retrieval
In an indexed sequential file _____.
the field on which the file is sequenced must be indexed
Consider relations A and B. Relation A represents the entity on the "one side" of a one-to-many relationship; Relation B represents the entity on the "many side" of the one-to-many relationship. The delete rule between relations A and B is set-to-null. If an attempt is made to delete a record in relation A and its primary key value appears as a foreign key value in one or more records of relation B ____.
the record in relation A will be the only record deleted and the foreign key values in relation B that match the primary key value of the record in relation A will be updated to null
Consider relations A and B. Relation A represents the entity on the "one side" of a one-to-many relationship; Relation B represents the entity on the "many side" of the one-to-many relationship. The delete rule between relations A and B is restrict. If an attempt is made to delete a record in relation B ____.
the record in relation B will be the only record deleted and no other changes will occur
An access method is _____.
the way that data is retrieved based on the file organization in use
Consider Table A on the "one side" of a one-to-many relationship and Table B on the "many side" of the relationship. The "repeating groups" in Table B may be considered for merging into the related records of Table A if ____.
there is a small number of occurrences of the repeating groups of Table B for each record of Table A
A ternary relationship involves ____ entity type(s).
three
The goal of logical database design is ____.
to create well-structured tables that properly reflect the company's business environment
Physical database design is necessary ____.
to improve the performance of the run-time environment.
In a magnetic disk device, the reason for storing data on a cylinder-wise basis is _____.
to minimize access arm movement in order to improve performance
In a magnetic disk device, the number of positions to which the access arm mechanism can move is equal to the number of _____.
tracks on a recording surface
The term that describes one non-key field of a table being dependent on another non-key field of the table is ____.
transitive dependency
