Relational Database Concepts

Q1. In a relational database, a table is also called a:

1. A.Tree
2. B.Graph
3. C.Document
4. D.Relation✓ Correct

Report an error in this question

Q2. A row in a relational table is called a:

1. A.Schema
2. B.Attribute
3. C.Domain
4. D.Tuple✓ Correct

Report an error in this question

Q3. A column in a relational table is called:

1. A.An attribute✓ Correct
2. B.A relation
3. C.A key value
4. D.A tuple

Report an error in this question

Q4. A primary key must be:

1. A.Unique and not null✓ Correct
2. B.Duplicate in values
3. C.Foreign key based
4. D.Nullable and optional

Report an error in this question

Q5. A foreign key is:

1. A.A key used only for sorting records in a particular order
2. B.The first column of any table regardless of its data content
3. C.An attribute that is always unique across all related tables
4. D.An attribute that references the primary key of another table✓ Correct

Report an error in this question

Q6. The domain of an attribute specifies:

1. A.The number of rows containing that attribute
2. B.The name assigned to identify that attribute
3. C.The set of allowed values for that attribute✓ Correct
4. D.The table name where the attribute exists

Report an error in this question

Q7. The degree of a relation refers to:

1. A.The number of tables in database
2. B.The number of tuples (rows) stored
3. C.The number of keys in the schema
4. D.The number of attributes (columns)✓ Correct

Report an error in this question

Q8. The cardinality of a relation refers to:

1. A.The number of keys in the table
2. B.The number of foreign key links
3. C.The number of tuples (rows)✓ Correct
4. D.The number of attributes (columns)

Report an error in this question

Q9. Which of the following is a property of a relational table?

1. A.Rows must be ordered
2. B.Each row is unique✓ Correct
3. C.Columns can be duplicated
4. D.Attributes are ordered

Report an error in this question

Q10. NULL in a database represents:

1. A.An empty string character
2. B.A zero numeric value only
3. C.A space character in data
4. D.An unknown or missing value✓ Correct

Report an error in this question

Q11. A candidate key is:

1. A.Any arbitrary attribute present in the table
2. B.The same concept as a foreign key reference
3. C.A minimal superkey that uniquely identifies tuples✓ Correct
4. D.Always the first column defined in the schema

Report an error in this question

Q12. A superkey is:

1. A.Any set of attributes that uniquely identifies tuples✓ Correct
2. B.A key that is permitted to contain NULL values
3. C.Always limited to a single attribute in the table
4. D.The same concept as a foreign key in a relation

Report an error in this question

Q13. Referential integrity constraint ensures that:

1. A.A foreign key value must match a primary key value in the referenced table or be NULL✓ Correct
2. B.All columns across every table in the database must have the same compatible data type
3. C.All tables in the database schema must have exactly the same total number of data rows
4. D.Primary key values can be duplicated across different rows within the same data table

Report an error in this question

Q14. Entity integrity constraint states that:

1. A.Foreign keys must always be unique in tables
2. B.Tables must have at least one row of data
3. C.All attributes in every row must have values
4. D.No primary key attribute can have a NULL value✓ Correct

Report an error in this question

Q15. An alternate key is:

1. A.A composite key made up of two or more attributes
2. B.A candidate key that is not chosen as the primary key✓ Correct
3. C.A key that is permitted to contain NULL value entries
4. D.The same concept as a foreign key in another table

Report an error in this question

Q16. A composite key is:

1. A.A key with only one single attribute value
2. B.A foreign key referencing another table
3. C.A key that allows NULL values in rows
4. D.A key consisting of two or more attributes✓ Correct

Report an error in this question

Q17. Which of the following is NOT a relational integrity constraint?

1. A.Entity integrity
2. B.Sequential constraint✓ Correct
3. C.Referential integrity
4. D.Domain constraint

Report an error in this question

Q18. A relation schema defines:

1. A.Only the primary key definition of the relation in question
2. B.The structure of a relation including attribute names and domains✓ Correct
3. C.The actual data values currently stored within the relation
4. D.Only the foreign keys that reference other related tables

Report an error in this question

Q19. In relational algebra, the Cartesian product of two relations R and S produces:

1. A.All possible combinations of tuples from R and S✓ Correct
2. B.The intersection of tuples in both R and S
3. C.Only tuples that match on common attributes
4. D.The union of all tuples from both R and S

Report an error in this question

Q20. A relation in 1NF requires that:

1. A.The table has only one column of values
2. B.There are no foreign keys in the relation
3. C.All values are strictly numeric in type
4. D.All attribute values are atomic (indivisible)✓ Correct

Report an error in this question

Q21. Codd's Rule 0 (Foundation Rule) states:

1. A.SQL is the only query language allowed for use within the database system
2. B.Indexes are mandatory for every attribute present in all database tables
3. C.All data must be stored exclusively in flat files without any table structure
4. D.A relational DBMS must manage data entirely through its relational capabilities✓ Correct

Report an error in this question

Q22. The information rule (Codd's Rule 1) states that:

1. A.Pointers can be used to represent data relationships
2. B.All information must be represented as values in tables✓ Correct
3. C.Metadata need not be stored in tables or relations
4. D.Data can be stored in external files outside the system

Report an error in this question

Q23. A relation is in BCNF if:

1. A.For every non-trivial functional dependency X to Y, X is a superkey✓ Correct
2. B.All attributes in the relation are prime (part of some key)
3. C.It has no multivalued dependencies among any of its attributes
4. D.It satisfies only the requirements of first normal form (1NF)

Report an error in this question

Q24. The closure of a set of attributes X (X+) under a set of functional dependencies is:

1. A.The set of all foreign keys that reference attribute X
2. B.The set of all attributes functionally determined by X✓ Correct
3. C.The total number of individual attributes within X
4. D.The set of all tables in the database containing X

Report an error in this question

Q25. Armstrong's axioms include all EXCEPT:

1. A.Augmentation
2. B.Reflexivity
3. C.Distribution✓ Correct
4. D.Transitivity

Report an error in this question

Q26. A lossless-join decomposition guarantees that:

1. A.The original relation can be reconstructed by joining the decomposed relations✓ Correct
2. B.No foreign keys are ever needed between the resulting decomposed relations
3. C.Join operations are always faster when applied to the decomposed relations
4. D.Some data will always be permanently lost during the decomposition process

Report an error in this question

Q27. The dependency preservation property ensures that:

1. A.Only primary key dependencies are preserved during the decomposition of tables
2. B.All functional dependencies can be checked within individual decomposed relations✓ Correct
3. C.No dependencies are maintained after decomposition of the original relation
4. D.Dependencies are stored separately from the decomposed relation structures

Report an error in this question

Q28. A surrogate key is:

1. A.A system-generated unique identifier with no business meaning✓ Correct
2. B.A natural key derived directly from the business domain
3. C.A composite key made up of multiple business attributes
4. D.A foreign key referencing a primary key in another table

Report an error in this question

Q29. Codd defined how many rules for a fully relational database?

1. A.12 rules (numbered 0-12, so 13 total)✓ Correct
2. B.10 rules (numbered 1 through 10 only)
3. C.5 rules (covering the basic properties)
4. D.20 rules (for comprehensive coverage)

Report an error in this question

Q30. The Closed World Assumption in relational databases means:

1. A.Facts not present in the database are considered false✓ Correct
2. B.Nothing stored in the database is considered to be true
3. C.All possible facts about the domain are stored in it
4. D.The database cannot be modified once it has been created

Report an error in this question