Database Management Quiz Section 2

A unique identifier must be made up of more than one attribute? (T/F)

False

In the relational model, relationships between relations or tables are created by using? Candidate Keys Primary Keys Foreign Keys Composite Keys

Foreign Keys

A relationship is transformed from logical to physical model using _________. Secondary Keys Candidate Keys Foreign Key Composite Keys

Foreign keys

An ERD created using ERDish is a __________ representation of entities and their relationships to each other. technical graphical textual hierarchical

Graphical

When creating entities in a logical model you must follow these rules: (Choose Two) o Name them in Singular o Exclude Attributes o Name them in Plural o Include Attributes

Name them in singular, include attributes

Entities are usually _____________. o Adverbs o Adjectives o Nouns o Verbs

Nouns

Which of the following is NOT a relationship type? -Many to Many -Someone to None -One to One -One to Many

Some to None

A ___ is a collection of records

Table

The logical model's entities, attributes, unique identifiers and relationships map to the physical model's _________________. Optionality and Cardinality Files, records, fields and data values Tables, columns, primary keys and foreign keys

Tables, columns, primary and foreign keys

Which of the following statements is true regarding Implementation-Free logical models? The model does not need to implemented on a DBMS. The model changes depending on operating system that is being used. The model changes depending on the relational database software being used The model stays the same regardless of the DBMS or operating system used.

The model stays the same regardless of the DBMS or operating system used

Which of the following are reasons to create a conceptual model? (3) o They capture current and future needs. o They capture the implementation details of the physical model. o They capture the data values. o They model functional and informational needs. o They accurately describe what a physical model will contain.

They capture current and future needs, they model functional and informational needs, and they accurately describe what a physical model will contain

The conceptual model does all of the following except: -Takes into account regulations and laws governing the industry being addressed. -Describes the needs of the business. -Prevents mistakes and misunderstandings. -Documents type of operating system to be used.

Documents type of operating system to be used

The physical model shows all table structures (T/F)

True

To identify an attribute as part of a unique identifier on an ER diagram, the # symbol goes in front of it. (T/F)

True

When mapping a relationship for an ERD diagram both sides of the relationship have to be mapped. (T/F)

True

The candidate UID that is chosen to identify an entity is called the Primary UID; other candidate UIDs are called Secondary UIDs. o No, each Entity can only have one UID, the secondary one. o No, after UIDs are first sorted, the first one is called the Primary UID, the second is the Secondary UID, etc. o No, it is not possible to have more than one UID for an Entity. o Yes, this is the way UID's are named.

Yes, this is the way UID's are named

Data Integrity ensures ____ in the information

no duplication

ERDish includes all of the following except: - Optionality - Cardinality - Data Values - Relationship Names

Data values

What does single table refer to? (Choose Two) (Choose all correct answers) A database where all of the data is stored in one large table. Non-relational systems that typically store each table and index in separate files and often do not support the SQL language. A type of database storage method where all of the data elements are stored on top of each other. A fully-relational database system like Microsoft's SQL Server or Oracle's database systems.

A database where all of the data is stored in one large table, non-relational systems that typically store each table and index in separate files and often do not support SQL

Which attribute counts as a volatile attribute? -Date of birth -Eye color -Race -Age

Age

Something can have a lot of characteristics but may not have a descriptive "number," to be able to identify one instance of an object like that an ______ UID is used

Artificial

In this course, we use the __________ notation for ERD modeling. o Bachman o Barker o Information Engineering o None of the above

Barker

Which of the following are true about Cardinality? (Choose 2) -Cardinality specifies a counting number (like 1,2,3,4,etc) in a relationship -Cardinality specifies whether something is required or not -Cardinality tells "how many" -Cardinality specifies only singularity or plurality, but not a specific plural number

Cardinality specifies "how many" & Cardinality specifies only sungularity or plurality, but not a specific plural number

An entity may have which of the following? -Experiences -Instances -Tables -None of the above

Instances

In a relational database system, the next step after creating a conceptual data model is to convert it to a _________ . External data model Internal data model Logical data model An entity-relation data model

Logical data model

A ____ relationship is a relationship between an entity and itself

Recursive

A candidate UID that does not get chosen to become the primary UID is called a ____

Secondary UID

In an ERD diagram how is cardinality represented? (2) - With a crow's foot - With a single toe - With a solid line - With a dotted line

With a crow's foot & With a single toe

A relationship can be between ____________. two entities an entity and itself multiple entities | all of the above

all of the above