Free Test Structure of Relationa... – Databas...

Q1: In a relational database, data is organized into?

A. Tables B. Graphs C. Trees D. Sets

Q2: What is a tuple in a relational table?

A. A row B. A column C. A database D. A key

Q3: What is an attribute in a relational table?

A. A column B. A row C. A table D. A key

Q4: What uniquely identifies a tuple in a table?

A. Primary key B. Foreign key C. Candidate key D. Composite key

Q5: What does a foreign key do?

A. References a primary key in another table B. Identifies tuples uniquely C. Stores user passwords D. Creates indexes

Q6: Which of the following is a property of relational tables?

A. All rows are unique B. All columns are unique C. Rows and columns can be duplicated D. None of these

Q7: What is a candidate key?

A. A key that can uniquely identify tuples B. A foreign key C. A key that is always composite D. An attribute that cannot be null

Q8: What is a composite key?

A. A key made of multiple attributes B. A key with a single attribute C. A foreign key D. A primary key

Q9: What does NULL represent in a relational table?

A. Unknown or missing value B. A zero value C. Empty string D. A primary key

Q10: Which constraint ensures no duplicate rows?

A. Primary key constraint B. Foreign key constraint C. Unique constraint D. Check constraint

Q11: What is a relation schema?

A. Definition of table structure B. Actual table data C. User interface D. Database hardware

Q12: Which of the following represents the degree of a relation?

A. Number of attributes B. Number of tuples C. Number of keys D. Number of indexes

Q13: What is the cardinality of a relation?

A. Number of tuples B. Number of attributes C. Number of keys D. Number of indexes

Q14: Which of the following is NOT a valid relational operation?

A. Join B. Select C. Project D. Rotate

Q15: What is the result of the project operation?

A. Subset of columns B. Subset of rows C. Entire table D. Union of tables

Q16: Which operation selects tuples based on a condition?

A. Select B. Project C. Join D. Union

Q17: What is a natural join?

A. Join on common attributes automatically B. Join with all possible combinations C. Join with no condition D. Join of one tuple

Q18: Which of the following is a unary operation in relational algebra?

A. Select B. Join C. Union D. Intersection

Q19: Which operation combines two relations with the same schema?

A. Union B. Select C. Project D. Join

Q20: What is referential integrity?

A. Foreign key must reference a valid primary key B. Primary key is unique C. Null values not allowed D. Keys are always numeric

Quiz for Structure of Relational Databases