IS 301 - Midterm

A foreign key must exist in both tables that have a relationship. True False

False

A manager and a programmer usually have the same view of the same data. True False

False

All RDBMSs enforce integrity rules automatically. True False

False

All simple attributes are also single-valued. True False

False

Database designers determine the data and information that yield the required understanding of the entire business. True False

False

End-user interfaces require the end user to manually generate SQL code. True False

False

Which of the following is true of business rules? They allow the designer to set company policies with regard to data. They allow the designer to develop business processes. They can serve as a communication tool between the users and designers. They provide a framework for the company's self actualization.

They can serve as a communication tool between the users and designers.

Initially the files within a computer file system were similar to manual files. True False

True

M:N relationships are not appropriate in a relational model. True False

True

The only way to access the data in a database is through the DBMS. True False

True

____ data exist in a format that does not lend itself to processing that yields information. Structured Semistructured Unstructured Historical

Unstructured

The key to correctly determining the cardinality of a relationship between two entities is to evaluate the relationship from ____. the "One" end of the relationship the "Many" end of the relationship the entity that will have the most members (e.g. more STUDENTS than COURSES) both ends - each entity in turn

both ends - each entity in turn

A(n) ____ is a restriction placed on the data. attribute entity relationship constraint

constraint

A ____ database supports data distributed across several different sites. single-user multiuser centralized distributed

distributed

Attributes may share a ____. name domain location table

domain

An entity is said to be ____-dependent if it can exist in the database only when it is associated with another related entity occurrence. existence relationship business weak

existence

Accurate, relevant, and timely information is the key to ____. data management good decision making knowledge understanding

good decision making

Knowing the ____ number of entity occurrences is very helpful at the application software level. maximum minimum approximate maximum and minimum

maximum and minimum

A(n) ____ join links tables by selecting only the rows with common values in their common attribute(s). equal unique foreign natural

natural

No data entry at all is known as a(n) ____. nil null empty zero

null

The ____ model uses the concept of inheritance. You Answered relational network object-oriented entity relationship

object-oriented

End-user data is ____. raw facts about the end-user raw facts of interest to the end-user data about data accurate, relevant and timely information

raw facts of interest to the end-user

A ____ key is defined as a key that is used strictly for data retrieval purposes. lookup foreign candidate secondary

secondary

The ____ is actually a system-created database whose tables store the user/designer-created database characteristics and contents. meta dictionary schema data dictionary system catalog

system catalog

A(n) ____ database is designed to support a company's day-to-day operations. desktop workgroup enterprise transactional

transactional

The preferred relationship cardinality in a relational database implementation is ____. 1 : 1 1 : M 1 : R M : N

1 : M

The ____ relationship should be rare in any relational database design. 1:1 1:M M:1 M:N

1:1

Hard disk drives are mechanical devices with moving parts whereas Random Access Memory (RAM) chips are solid state devices. Regarding virtual memory on database servers, which of the following is closest to the performance difference between them? RAM is 100 times slower than a hard disk RAM is 200 times slower than a hard disk A hard disk is 100 times slower than RAM A hard disk is 200 times slower than RAM

A hard disk is 200 times slower than RAM

____ relationships are most common. Unary Binary Ternary Higher-degree

Binary

____ are important because they help to ensure data integrity. Attributes Entities Relationships Constraints

Constraints

____ are normally expressed in the form of rules. Attributes Entities Relationships Constraints

Constraints

The step, ____, occurs first in the process of building an ERD. Develop the initial ERD. Create a detailed narrative of the organization's description of operations. Identify the attributes and primary keys that adequately describe the entities. Identify the business rules based on the description of operations.

Create a detailed narrative of the organization's description of operations.

____ exists when different versions of the same data appear in different places. Data inconsistency Data consistency Better data integration Improved decision making

Data inconsistency

Attributes do not have a domain. True False

False

Entities are types of attributes. True False

False

Structural dependence exists when it is possible to make changes in the file structure without affecting the application program's ability to access the data. True False

False

The DBMS reveals much of the database's internal complexity to the application programs and users. True False

False

The one-to-many (1:M) relationship is easily implemented in the relational model by putting the foreign key of the "1" side in the table of the "many" side as a primary key. True False

False

The order of the rows and columns is important to the DBMS. True False

False

____ is used to reveal the meaning of data. Raw facts Knowledge Formatting Information

Information

____ data can have only a true or false (yes or no) values. Logical Character Date Numeric

Logical

In a relational database, you cannot implement a ____ relationship between two entities, such as STUDENT and COURSE. Some modeling tools will not allow the designer to draw an Entity Relationship Diagram (ERD) that contains such a relationship. 1-to-Many Many-to-Many 1-to-1 Many-to-1

Many-to-Many

The ____ constraint can be placed on a column to ensure that every row in the table has a value for that column. HAS VALUE NOT NULL MUST HAVE VALUE NOT EMPTY

NOT NULL

____, also known as RESTRICT, yields values for all rows found in a table that satisfy a given condition. INTERSECT UNION DIFFERENCE SELECT

SELECT

Most data you encounter is best classified as ____. Structured Semistructured Unstructured Historical

Semistructured

A data model is usually graphical. True False

True

A proper understanding of the concept and use of keys in a relational database model is very important. True False

True

A strong relationship exists if the primary key of the related entity contains at least one primary key component of the parent entity. True False

True

Attributes can share a domain. True False

True

Connectivities and cardinalities are established by business rules. True False

True

Each table in a relational database must have a primary key. True False

True

Historically, a manual file system was composed of a system of file folders and filing cabinets. True False

True

Numeric data are data on which you can perform meaningful arithmetic procedures. True False

True

Tables must have the same attribute characteristics (the columns and domains must be compatible) to be used in a UNION. True False

True

The DBMS cannot handle multivalued attributes. True False

True

The ER diagram represents the conceptual database as viewed by the end user. True False

True

The ER model may refer to a specific table row as an "entity instance." True False

True

The ER model may refer to a specific table row as an "entity occurrence." True False

True

The word "entity" in the ER model corresponds to a table. True False

True

You should always load data from the 1 side of a 1:M relationship. True False

True

____ combines all rows from two tables, excluding duplicate rows. INTERSECT UNION DIFFERENCE SELECT

UNION

A ____ relationship exists when two entities are associated. unary binary ternary weak

binary

Making sure all ____ are identified is a very important part of a database designer's job. business rules cardinalities derived attributes relationships

business rules

The database structure in a DBMS is stored as a ____. file collection of files set of key/value pairs collection of queries

collection of files

A ____ attribute can be further subdivided to yield additional attributes. composite simple single-valued multivalued

composite

A ____ identifier is composed of more than one attribute. primary foreign composite domain

composite

A(n) ____ model represents a global view of the database as viewed by the entire organization. external conceptual internal physical

conceptual

The ERD represents the ____ database as viewed by the end user. condensed physical logical Conceptual

conceptual

In the context of a database table, the statement "A ____ B" indicates that if you know the value of attribute A, you can look up the value of attribute B. contains is related to owns determines

determines

A(n) ____ database is used by an organization and supports many users across many departments. desktop workgroup enterprise transactional

enterprise

In order to avoid making null entries, another option is to use a "placeholder," such as -99 for an agent code where no agent has yet been assigned to a customer. This type of "placeholder" is properly known as a ____. flag placeholder nil substitution

flag

Which two of the following data problems are relational databases intended to minimize? frequent null entries frequent duplicate entries storage of data in tables user-accessible queries

frequent null entries frequent duplicate entries

An application programming interface (API) is a standard tool that provides data structure ____ relative to an an application. keys performance dependence independence

independence

A derived attribute ____. must be stored physically within the database has many values is typically not physically stored within the database must be based on the value of three or more attributes

is typically not physically stored within the database

The ____ type of attribute cannot be created in a DBMS. derived multivalued simple composite

multivalued

Ideally, an entity identifier is composed of ____ attribute(s). zero one two six

one

You began with a dataset that occupied 60 columns in a single table. In order to achieve the ideal of completely minimalized nulls or redundancy, you have broken this data into 13 related tables that would make E.F. Codd proud. A potential problem with this design is that it may have a(n) ____ problem. substitution inversion RDBMS performance

performance

A ____ should be a derived attribute. person's name person's age person's social security number person's phone number

person's age

Since it is used to link the tables that originally were related in a M:N relationship, the composite entity structure includes—as foreign keys—at least the ____ keys of the tables that are to be linked. composite super primary unique

primary

Controlled ____ makes a relational database work. relations logic chaos redundancy

redundancy

MySQL is an example of a(n) ____. hierarchical model file system data model relational data model XML data model

relational data model

A verb associating two nouns in a business rule translates to a(n) ____ in the data model. entity attribute relationship constraint

relationship

A key design theme is that once the business rules have been identified, the database should reflect these rules by capturing the maximum possible ____, also known as ____. Correct! semantics data information meaning

semantics meaning

A challenge with naming components of a database in a manner that tends toward self-documentation is the solution provider/designer may have a strong need for ____. managerial input standardization conducting interviews data storage space

standardization

Another word for existence-independent is ____. weak alone unary strong

strong

When the PK of one entity contains the PK of a related entity, the relationship is ____. missing weak strong neutral

strong

A(n) ____ is perceived as a two-dimensional structure composed of rows and columns. table rowset attribute intersection

table

A ____ relationship exists when three entities are associated. unary binary ternary weak

ternary

In an ER diagram, primary keys may be indicated by the letters PK and by ____. underlining italics bolding the letter case

underlining

When you define a table's primary key, the DBMS automatically creates a(n) ____ index on the primary key column(s) you declared. key incomplete unique primary

unique

A design problem that can occur is by trying to include too many different attributes in a single table, some of the attributes can end up shared between tables, but not through Primary Key (PK) / Foreign Key (FK) relationships. As a result the database is prone to ____ anomalies. performance update null tuple

update