1. . Relational algebra is:
(A) A compression technique
(B) A non-procedural language
(C) A procedural query language used to retrieve data from relational databases
(D) An encryption method
2. . Relational calculus is:
(A) A procedural language
(B) A non-procedural query language based on predicate logic
(C) A compression method
(D) A backup system
3. . The basic operations in relational algebra include:
(A) Compress, Encrypt, Delete, Backup
(B) Select, Project, Union, Set Difference, Cartesian Product, Rename
(C) Join, Split, Encode, Decode
(D) None of the above
4. . The SELECT operation in relational algebra is used to:
(A) Retrieve columns
(B) Retrieve rows that satisfy a given condition
(C) Combine tables
(D) Delete records
5. . The PROJECT operation in relational algebra is used to:
(A) Retrieve rows
(B) Retrieve specific columns from a table
(C) Combine tables
(D) Encrypt data
6. . UNION operation in relational algebra:
(A) Combines tuples from two relations and removes duplicates
(B) Deletes rows
(C) Encrypts tables
(D) Compresses data
7. . SET DIFFERENCE operation in relational algebra:
(A) Encrypts tables
(B) Combines tables
(C) Compresses files
(D) Returns tuples that are in one relation but not in another
8. . CARTESIAN PRODUCT in relational algebra:
(A) Combines every tuple of one relation with every tuple of another relation
(B) Deletes duplicates
(C) Encrypts rows
(D) Compresses tables
9. . RENAME operation in relational algebra is used to:
(A) Compress files
(B) Encrypt tables
(C) Give a new name to a relation or attributes
(D) Delete old relations
10. . JOIN operation in relational algebra:
(A) Compresses data
(B) Deletes rows
(C) Combines related tuples from two relations based on a common attribute
(D) Encrypts tables
11. . Theta join is a type of join where:
(A) Only equality is used
(B) A condition other than equality is used to combine relations
(C) Only projection is used
(D) Only selection is used
12. . Equi-join is:
(A) A join based on inequality
(B) A join based on equality condition between attributes
(C) A projection operation
(D) A selection operation
13. . Natural join automatically:
(A) Compresses files
(B) Encrypts data
(C) Combines two relations based on common attributes with the same name
(D) Deletes duplicates only
14. . Tuple relational calculus (TRC) uses:
(A) Columns only
(B) Variables that represent tuples and formulas to specify queries
(C) Rows only
(D) Encryption keys
15. . Domain relational calculus (DRC) uses:
(A) Variables that represent attribute values rather than tuples
(B) Tuples only
(C) Columns only
(D) Compressed data
16. . In relational calculus, queries specify:
(A) How to compress tables
(B) How to retrieve data only
(C) What to retrieve, not how to retrieve it
(D) How to encrypt data
17. . Safety in relational calculus means:
(A) Queries compress tables
(B) Queries return all possible tuples
(C) Queries return a finite number of tuples
(D) Queries encrypt data
18. . Difference between relational algebra and calculus is:
(A) Both are non-procedural
(B) Both are procedural
(C) Algebra is procedural; calculus is non-procedural
(D) Algebra compresses data, calculus encrypts
19. . Aggregation operations in relational algebra include:
(A) SELECT, PROJECT
(B) SUM, AVG, COUNT, MIN, MAX
(C) JOIN only
(D) RENAME only
20. . The main purpose of Relational Algebra & Calculus is to:
(A) Delete old records
(B) Compress tables
(C) Encrypt files
(D) Provide formal foundation for querying and manipulating relational databases