1Z0-006 Fundamental Database Concepts Questions and Answers — Questions and Answers
Question 1: Which of the following BEST describes the primary purpose of the relational model in database design?
- To store data in a hierarchical structure, similar to a file system.
- To define relationships between data points using tables, rows, and columns, ensuring data consistency. (Correct answer)
- To create a flexible schema that allows for storing unstructured data like documents and media files.
- To manage physical data storage directly, optimizing for hardware performance.
Correct answer: To define relationships between data points using tables, rows, and columns, ensuring data consistency.
The relational model's core purpose is to organize data into tables (relations) with rows (tuples) and columns (attributes). This structure allows for the explicit definition of relationships between different data points, which helps maintain data consistency and integrity.
Question 2: A database administrator is designing a table to store employee information, including their skills. To avoid data redundancy, they decide to create a separate 'Skills' table and a 'Employee_Skills' table to link employees to their skills. This process is an example of what fundamental database concept?
- Data Encryption
- Transaction Control
- Normalization (Correct answer)
- Data Warehousing
Correct answer: Normalization
Normalization is the process of organizing columns and tables in a relational database to minimize data redundancy. By creating separate tables for employees and skills and a third table to link them, the administrator is eliminating redundant data (not repeating skill names for each employee) and improving data integrity, which is the primary goal of normalization.
Question 3: In an Oracle database, which of the following are considered schema objects?
- Users, Roles, and Profiles
- Tablespaces, Datafiles, and Control Files
- The System Global Area (SGA) and Program Global Area (PGA)
- Tables, Views, Indexes, and Sequences (Correct answer)
Correct answer: Tables, Views, Indexes, and Sequences
Schema objects are logical structures of data owned by a database user. Common examples include tables, views, indexes, and sequences. Users, roles, and tablespaces are considered non-schema objects, and the SGA/PGA are memory structures.
Question 4: What is the key difference between Data Definition Language (DDL) and Data Manipulation Language (DML)?
- DDL commands are used to query data, while DML commands are used to grant user permissions.
- DDL defines and manages the structure of database objects, while DML is used to add, modify, or delete the data within those objects. (Correct answer)
- DDL commands like COMMIT and ROLLBACK manage transactions, while DML commands create tables and indexes.
- DDL is used for creating reports, while DML is used for database backup and recovery.
Correct answer: DDL defines and manages the structure of database objects, while DML is used to add, modify, or delete the data within those objects.
Data Definition Language (DDL) includes commands like CREATE, ALTER, and DROP, which are used to define the database schema and its objects. Data Manipulation Language (DML) includes commands like INSERT, UPDATE, and DELETE, which are used to manipulate the actual data stored within those objects.
Question 5: A developer needs to create a table to store customer orders. Each order must have a unique identifier. Which of the following constraints is MOST appropriate for the 'OrderID' column to ensure each row can be uniquely identified?
- FOREIGN KEY
- CHECK
- NOT NULL
- PRIMARY KEY (Correct answer)
Correct answer: PRIMARY KEY
A PRIMARY KEY constraint uniquely identifies each record in a table. It must contain unique values and cannot contain NULL values. This is the most suitable constraint for an OrderID column to ensure every order has a unique identifier.
Question 6: An Entity-Relationship Diagram (ERD) is used during the database design phase. What does a rectangle typically represent in an ERD?
- A relationship between two pieces of data
- An attribute or property of an object
- An entity, such as a person, place, or object, about which data is stored (Correct answer)
- An action or process performed by the database
Correct answer: An entity, such as a person, place, or object, about which data is stored
In an Entity-Relationship Diagram (ERD), a rectangle represents an entity. An entity is a real-world object, concept, or event about which data is collected, such as 'Customer', 'Product', or 'Order'.
1Z0-006 Fundamental Database Concepts Questions and Answers
Which of the following BEST describes the primary purpose of the relational model in database design?