Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

ISE 224 > Chapter 6 > Flashcards

Chapter 6 Flashcards

1
Q

The first step in the database design process is to create tables and columns from entities and attributes.

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

When creating a relational database design from E-R diagrams, first create a relation for each relationship.

A

False

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Each entity in the extended E-R model is represented as a table in the relational database design.

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

An entity needs to be examined according to normalization criteria before creating a table from it in the relational database design.

A

False

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

When creating a table in the relational database design from an entity in the extended E-R model, the attributes of the entity become the rows of the table.

A

False

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

By default, the identifier of the entity becomes the foreign key of the corresponding table.

A

False

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

The ideal primary key is short, numeric, and fixed.

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

A surrogate key is appropriate when the primary key of a table contains a lengthy text field.

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

One of the important properties of an attribute is whether or not it is required.

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

A surrogate key is a unique, system-supplied identifier used as the primary key of a table.

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

The values of a surrogate key have no meaning to the users.

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

A surrogate key should be considered when the key contains a lengthy text field.

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Whether or not an attribute is required is determined during the database modeling phase.

A

False

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

A null value is an attribute value that has been set to zero.

A

False

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Data types are consistent across all DBMS products.

A

False

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

A default value is the value the user enters into the row the first time the user enters data.

A

False

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

A data constraint is a limitation on data values.

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

The last step in creating a table is to verify table normalization.

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

One of the important properties of a column is whether or not it can have a NULL value.

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

A foreign key is a key that does not belong in any table.

A

False

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

In a relational database design, all relationships are expressed by creating a foreign key.

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

When the key of one table is placed into a second table to represent a relationship, the key is called a “relational key” in the second table.

A

False

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

To represent a 1:1 binary relationship in a relational database design, the key of one table is placed into the second table.

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

When placing a foreign key for a 1:1 relationship, the key of either table can be used as the foreign key in the other table.

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

In a 1:1 relationship, the foreign key is defined as an alternate key to make the DBMS enforce uniqueness.

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

In a 1:N relationship, the term “parent” refers to the table on the “many” side of the relationship.

A

False

27
Q

In 1:N relationships, the table on the “one” side is called the parent.

A

True

28
Q

In representing a 1:N relationship in a relational database design, the key of the table representing the parent entity is placed as a foreign key in the table representing the child entity.

A

True

29
Q

In representing a 1:N relationship in a relational database design, the key of the table representing the entity on the “many” side is placed as a foreign key in the table representing the entity on the “one” side of the relationship.

A

False

30
Q

To represent a 1:N relationship in a relational database design, an intersection table is created.

A

False

31
Q

In 1:N relationships, the table on the “many” side is called the child.

A

True

32
Q

To represent a one-to-many relationship in a relational database design, the key of the child table is placed as a foreign key into the other table.

A

False

33
Q

To represent an M:N relationship in a relational database design, a table is created to represent the relationship itself.

A

True

34
Q

To represent an M:N relationship in a relational database design, an intersection table is created.

A

True

35
Q

To represent an M:N relationship in a relational database design, in essence it is reduced to two 1:N relationships.

A

True

36
Q

The key of an intersection table is always the combination of the keys of both parents.

A

True

37
Q

In many-to-many relationships in a relational database design, the primary keys of both tables are joined into a composite primary key in the intersection table.

A

True

38
Q

An intersection table is always ID-dependent on both of its parent tables.

A

True

39
Q

An intersection table can have additional attributes besides the keys of its parent tables.

A

False

40
Q

Like all ID-dependent relationships, the parents of an association table are required.

A

True

41
Q

Association tables sometimes connect more than two entities.

A

True

42
Q

An ID-dependent table can be used to represent multivalued attributes.

A

True

43
Q

All identifying relationships are 1:N.

A

True

44
Q

When creating a table for an ID-dependent entity, both the key of the parent and the key of the entity itself must appear in the table.

A

True

45
Q

The design transformation for all IS-A relationships can be summarized by the phrase “place the key of the parent table in the child table.”

A

False

46
Q

When transforming an ID-dependent E-R data model relationship into a relational database design where the child entity is designed to use a surrogate key, the relationship changes to a weak but not ID-dependent relationship.

A

True

47
Q

When transforming supertype/subtype entities into a relational database design, an entity is created for the supertype only.

A

False

48
Q

When transforming supertype/subtype entities into a relational database design, the key of the supertype table is placed into the subtype table typically as the key.

A

True

49
Q

To represent an IS-A relationship in a relational database design, the IS-A relationship must be converted into a HAS-A relationship.

A

False

50
Q

Discriminator attributes can be represented in relational designs.

A

False

51
Q

When transforming supertype/subtype entities into a relational database design, all of the attributes for the supertype table are placed into the subtype relations.

A

False

52
Q

When transforming an extended E-R model into a relational database design, recursive relationships are treated fundamentally the same as other HAS-A relationships.

A

True

53
Q

Recursive M:N relationships are represented with an intersection table that shows pairs of related rows from a single table.

A

True

54
Q

Referential integrity constraints should disallow adding a new row to a child table when the foreign key does not match a primary key value in the parent table.

A

True

55
Q

A referential integrity constraint policy that insures that foreign key values in a table are correctly maintained when there is a change to the primary key value in the parent table is called cascading changes.

A

False

56
Q

A referential integrity constraint policy that insures that all rows containing a particular foreign key value in a table are eliminated from the table when the row containing the corresponding primary key value in a parent table is eliminated from the database is called cascading deletes.

A

True

57
Q

When the parent entity is required (M) in a relationship, every row of the child table must have a valid, non-null value of the foreign key.

A

True

58
Q

Cascading deletions are generally not used with relationships between strong entities.

A

True

59
Q

Cascading deletions are generally not used with relationships for weak child entities.

A

False

60
Q

If the parent is required, then a new child row must be created with a valid foreign key value.

A

True

61
Q

When the parent entity has a surrogate key, the enforcement actions are the same for both parent and child.

A

True

62
Q

When the child entity is required (M) in a relationship, there needs to be at least one child row for each parent row at all times.

A

True

63
Q

It is easy to enforce the referential integrity actions for M-M relationships.

A

False

ISE 224 (8 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions