1Z0-006 Fundamental Database Concepts 4

Question 1

What is the primary purpose of database normalization?

Accepted Answer

To reduce data redundancy and improve data integrity

Answer

Normalization organizes data to minimize redundancy and dependency, preventing update, insert, and delete anomalies.

Question 2

In an Entity-Relationship (ER) diagram, what does a diamond shape represent?

Accepted Answer

A relationship

Answer

In ER diagrams, diamond shapes represent relationships (associations) between entities, while rectangles represent entities and ovals represent attributes.

Question 3

What is a non-correlated subquery?

Accepted Answer

A subquery that executes independently of the outer query

Answer

A non-correlated subquery executes once independently and passes its result to the outer query, unlike a correlated subquery which references outer query columns.

Question 4

Which Oracle SQL function returns the current date and time including fractional seconds and timezone?

Accepted Answer

SYSTIMESTAMP

Answer

SYSTIMESTAMP returns the current date and time including fractional seconds and the database timezone, while SYSDATE returns only date and time without fractional seconds.

Question 5

What is a composite primary key?

Accepted Answer

A primary key composed of two or more columns together

Answer

A composite primary key uses multiple columns in combination to uniquely identify each row, where no single column alone provides uniqueness.

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

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

1Z0-006 Fundamental Database Concepts 4