Database Design & Development 1

Which best describes an entity?

• Is the association between two related processes

• Has cardinality (1:1, 1:N, or M:N)

• Shows if it can be null or no null

• Is a person, place or thing

• Is described with a verb phrase

What do the lines in an ERD represent?

• Hierarchies between processes

• Relationships among the data

• Plurality of data items

• Uniqueness of data items

• Primary keys

Which attribute is the KEY IDENTIFIER or the PRIMARY KEY?

• EmpID
• Degree
• Name
• Birthday

Which cardinality does this symbol represent?

• one or many
• zero or many
• zero or one
• many to many

Which cardinality does this symbol represent?

• zero or one
  zero or one
• zero or many
• one or many
• many to many

Which key uniquely identifies each record in an entity?

• Primary Key or Key Identifier

• Foreign Key

• Secondary Key

• Composite Key

Which of the following is an advantage of using a database system?

• security enforcement

• avoidance of redundancy

• reduced inconsistency

• all of these

When data is repeated over and over again in the database, what is this known as?

• data inconsistency

• data dependence

• data redundancy

• data isolation

Which database structures the data in a tree-like structure?

• network model

• object-oriented model

• relational model

• hierarchical model

In a relational database model, which one is referred to as an entity?

• a table

• a row

• a column

• a record