MIS Database Management Systems 1 — Questions and Answers
Question 1: Which type of database model organizes data into tables with rows and columns, linked by keys?
- Hierarchical model
- Relational model (Correct answer)
- Network model
- Object-oriented model
Correct answer: Relational model
The relational model organizes data into tables (relations) connected via primary and foreign keys, and is the basis for SQL-based databases.
Question 2: In a relational database, a PRIMARY KEY is best described as:
- A field that allows duplicate values
- A field that uniquely identifies each record in a table (Correct answer)
- A pointer to a record in another table
- A constraint that allows null values
Correct answer: A field that uniquely identifies each record in a table
A primary key uniquely identifies each row in a table and cannot contain null or duplicate values.
Question 3: Which SQL command is used to retrieve data from a database table?
- INSERT
- UPDATE
- SELECT (Correct answer)
- DELETE
Correct answer: SELECT
The SELECT statement is the SQL command used to query and retrieve data from one or more database tables.
Question 4: What does ACID stand for in the context of database transactions?
- Atomicity, Consistency, Isolation, Durability (Correct answer)
- Accuracy, Concurrency, Integrity, Dependency
- Atomicity, Concurrency, Integrity, Durability
- Accuracy, Consistency, Isolation, Dependency
Correct answer: Atomicity, Consistency, Isolation, Durability
ACID stands for Atomicity, Consistency, Isolation, and Durability — the four properties that guarantee reliable database transactions.
Question 5: A FOREIGN KEY in a relational database:
- Uniquely identifies a record within its own table
- Links a record in one table to a record in another table (Correct answer)
- Encrypts sensitive data within the table
- Prevents any changes to a table's structure
Correct answer: Links a record in one table to a record in another table
A foreign key is a field in one table that references the primary key of another table, establishing a relationship between the two tables.
Question 6: Which normal form eliminates partial dependencies by ensuring every non-key attribute depends on the whole primary key?
- First Normal Form (1NF)
- Second Normal Form (2NF) (Correct answer)
- Third Normal Form (3NF)
- Boyce-Codd Normal Form (BCNF)
Correct answer: Second Normal Form (2NF)
Second Normal Form (2NF) requires that all non-key attributes are fully functionally dependent on the entire primary key, eliminating partial dependencies.
Question 7: In database terminology, what is a 'schema'?
- A backup copy of the database
- The logical structure or blueprint defining the organization of data in a database (Correct answer)
- A query that retrieves data from multiple tables
- A record stored in a database table
Correct answer: The logical structure or blueprint defining the organization of data in a database
A schema is the logical structure that defines how a database is organized, including tables, columns, data types, and relationships.
MIS Database Management Systems 1
Which type of database model organizes data into tables with rows and columns, linked by keys?