1Z0-006 Data Modeling 2

Question 1

In an Entity-Relationship diagram, what does a double rectangle around an entity name signify?

Accepted Answer

A weak entity that depends on another entity for identification

Answer

A double rectangle denotes a weak entity, which cannot be uniquely identified by its own attributes alone and relies on a parent (owner) entity.

Question 2

Which normal form eliminates partial dependencies on a composite primary key?

Accepted Answer

Second Normal Form (2NF)

Answer

2NF removes partial dependencies, ensuring every non-key attribute depends on the whole composite primary key, not just part of it.

Question 3

A CUSTOMER can place zero or many ORDERS, and each ORDER must belong to exactly one CUSTOMER. How is this cardinality expressed?

Accepted Answer

One (CUSTOMER) to many (ORDER) with mandatory participation on ORDER side

Answer

This is a one-to-many relationship where ORDER has mandatory participation (must have a customer) and CUSTOMER has optional participation (may have no orders).

Question 4

What is a surrogate key in relational database design?

Accepted Answer

A system-generated artificial key with no business meaning

Answer

A surrogate key is a system-generated (e.g., auto-increment) identifier with no inherent business meaning, used to uniquely identify rows.

Question 5

In data modeling, what does 'domain' refer to?

Accepted Answer

The set of all valid values an attribute can hold

Answer

A domain defines the permissible set of values for an attribute, including data type, length, format, and constraints.

(1Z0-006) Oracle Database Foundations Associate Practice Test

(1Z0-006) Oracle Database Foundations Associate Practice Test

1Z0-006 Data Modeling 2