Midterm (Ch 1-6)

true

A candidate key is an attribute, or combination of attributes, that uniquely identifies a row in a relation.

the key must indicate the row's position in the table.

A candidate key must satisfy all of the following conditions EXCEPT:

true

A cascading delete removes all records in other tables associated with the record to be deleted.

explain plan

A command used in Oracle to display how the query optimizer intends to access indexes, use parallel servers and join tables to prepare query results is the:

false

A composite key consists of only one attribute.

extent

A contiguous section of disk storage space is called a(n):

extra space and update time.

A disadvantage of partitioning is:

heap file organization

A file organization where files are not stored in any particular order is considered a:

transitive dependency

A functional dependency between two or more nonkey attributes is called a:

universal data model

A generic or template data model that can be reused as a starting point for a data modeling project is called a(n):

data model

A graphical system used to capture the nature and relationships among data is called a(n):

track missing data with special reports.

A method for handling missing data is to:

parallel query processing

A method that speeds query processing by running a query at the same time against several partitions of a table using multiprocessors is called:

clustering

A method to allow adjacent secondary memory space to contain rows from several tables is called:

true

A pointer is a field of data that can be used to locate a related field or record of data.

enterprise key

A primary key whose value is unique across all relations is called a(n):

true

A range control limits the set of permissible values that a field may assume.

well-structured

A relation that contains minimal redundancy and allows easy use is considered to be:

true

A well-structured relation contains minimal redundancy and allows users to manipulate the relation without errors or inconsistencies.

server

A workgroup database is stored on a central device called a(n):

completeness

A(n) ________ constraint is a type of constraint that addresses whether an instance of a supertype must also be an instance of at least one subtype.

pointer

A(n) ________ is a field of data used to locate a related field or record.

false

Adding notations to the EER diagram regarding data volumes and usage is of no value to the physical design process.

a one-to-many relationship.

All of the following are common denormalization opportunities EXCEPT:

true

All values that appear in a column of a relation must be taken from the same domain.

primary key

An attribute (or attributes) that uniquely identifies each row in a relation is called a:

foreign key

An attribute in a relation of a database that serves as the primary key of another relation in the same database is called a:

required attribute

An attribute of an entity that must have a value for each entity instance is a(n):

composite identifier

An attribute that uniquely identifies an entity and consists of a composite attribute is called a(n):

true

An attribute whose values can be calculated from related attribute values is called a derived attribute.

false (primary key!)

An enterprise key is a foreign key whose value is unique across all relations.

true

An entity cluster should focus on some area of interest to some community of users, developers or managers.

associative entity

An entity that associates the instances of one or more entity types and contains attributes specific to the relationships is called a(n):

false

An entity type on which a strong entity is dependent is called a covariant entity.

range control

An integrity control supported by a DBMS is:

false

CASE tools can model more complex data relationships, such as ternary relationships.

false

Characteristics of the structure of the database are generally changed during the implementation phase of the database development process.

true

Clustering allows for adjacent secondary memory locations to contain rows from several tables.

false

Creating a data model from a packaged data model requires much more skill than creating one from scratch.

tables

Data is represented in the form of:

true

Data structures include data organized in the form of tables with rows and columns.

True

Database architects establish standards for data in business units.

enterprise data modeling

Database development begins with ________, which establishes the range and general contents of organizational databases.

false

Database development begins with the design of the database.

True

Development starts from scratch with the traditional file processing approach because new file formats, descriptions, and file access logic must be designed for each new program.

true

Efficient database structures will be beneficial only if queries and the underlying database management system are tuned to properly use the structures.

true

Fast data retrieval is one factor to consider when choosing a file organization for a particular database file.

false

Free range partitioning is a type of horizontal partitioning in which each partition is defined by a range of values for one or more columns in the normalized table.

false

Horizontal partitioning is very different from creating a supertype/subtype relationship.

when different categories of a table's rows are processed separately.

Horizontal partitioning makes sense:

true

In a sequential file, the records are stored in sequence according to a primary key value.

only one supertype

In a supertype/subtype hierarchy, each subtype has:

supertypes

In a supertype/subtype hierarchy, subtypes that are lower in the hierarchy inherit attributes from not only their immediate supertype but from all ________ in the hierarchy.

M:N relationships

In packaged data models, strong entities always have ________ between them.

create table

In the SQL language, the ________ statement is used to make table definitions.

false

In the figure below, Name would be an ideal identifier: STUDENT(SID, Name, Address)

an associative entity

In the figure below, what is depicted? same concept as Fig 4-13

false

In the figure shown below, a rental unit can be both an apartment and a house but must be at least one. (RENTAL UNIT is supertype to APARTMENT and HOUSE; one bar to circle, O in circle)

true

In the figure shown below, a rental unit has to be either a house or an apartment. (RENTAL UNIT is supertype to HOUSE and APARTMENT; two bars to circle, d in circle)

true

Multitier client/server database applications contain a business logic layer.

true

One decision in the physical design process is selecting structures.

A component is always used in only one item.

Referring to the figure below, which of the following is NOT true? ITEM(Item_No(PK, FK), Name, Unit_Cost) COMPONENT(Item_No(PK), Component_No(PK), Quantity)

false

Regardless of the business situation, a member of the supertype is always a member of more than one subtype.

false

SOX stands for the Sorbet-Oxford Act.

true

Security is one advantage of partitioning.

true

Sensitivity testing involves ignoring missing data unless knowing a value might significantly change results.

false

Supertype/subtype relationships should be used when the instances of a subtype participate in no relationships which are unique to that subtype.

true

The columns of a relation can be interchanged without changing the meaning or use of the relation.

True

The data repository assists database administrators in enforcing standards.

false

The entity integrity rule states that a primary key attribute can be null.

entity cluster

The figure below is an example of a(n): (EER diagram with borders surrounding named groups of entitties; Fig 3-13)

not partial specialization ???

The following diagram shows: similar to Fig 3-2

false

The following figure is an example of total specialization. (STUDENT is supertype ... no rules/constraints implied)

total specialization

The following figure is an example of: (ROOM is supertype of CLASSROOM, LAB, OFFICE; two bars to circle, O in circle)

supertype/subtype hierarchy

The following figure shows a: similar to Fig 3-10

false

The logical database design always forms the best foundation for grouping attributes in the physical design.

strong entitities

The most common types of entities are:

false

The query processor always knows the best way to process a query.

Part_Type

The subtype discriminator in the figure below is: Fig 3-9

False

The term legacy system refers to a newly installed database management system.

map data to be used from package to data in current databases.

The third step in the data modeling process with a packaged data model is:

false

The total specialization rule states that an entity instance of a supertype is allowed not to belong to any subtype.

one must be able to check the output of a CASE tool.

Understanding the steps involved in transforming EER diagrams into relations is important because:

false

Unlike columns, the rows of a relation may not be interchanged and must be stored in one sequence.

true

VarChar2 would be appropriate for a user that wanted a text datatype for LastName that would only consume the required space.

true

Vertical partitioning means distributing the columns of a table into several separate physical records.

true

When a regular entity type contains a multivalued attribute, two new relations are created.

true

When normalizing, the goal is to decompose relations with anomalies to produce smaller, well-structured relations.

false

When transforming a one-to-one relationship, a new relation is always created.

false

When transforming a unary many-to-many relationship to relations, a recursive foreign key is used.

true

When two or more attributes describe the same characteristic of an entity, they are synonyms.

No two rows in a relation are identical.

Which of the following are properties of relations?

inconsistent

Which of the following is NOT a characteristic of a good business rule?

Relates to a technical characteristic of the system

Which of the following is NOT a good characteristic of a data name?

Sample data can reverse database implementation errors.

Which of the following is NOT a reason to create an instance of a relational schema with sample data?

strong

Which of the following is an entity that exists independently of other entity types?

sequential

Which type of file is most efficient with storage space?

tablespace

Within Oracle, the named set of storage elements in which physical files for database tables may be stored is called a(n):

false

You will never need to map data in current databases to data in a packaged data model.

modification

________ are anomalies that can be caused by editing data in tables.