1. . A distributed database is:
(A) A single central database
(B) A database in which data is stored across multiple physical locations connected via a network
(C) A compressed backup
(D) An encrypted file
2. . Main goals of a distributed database include:
(A) Encryption only
(B) Compression only
(C) Transparency, reliability, and efficiency
(D) Deleting old data automatically
3. . Data fragmentation in distributed databases is:
(A) Deleting old records
(B) Encrypting tables
(C) Compressing tables
(D) Dividing a database into smaller pieces called fragments
4. . Horizontal fragmentation means:
(A) Compressing rows
(B) Dividing a table into subsets of columns
(C) Encrypting rows
(D) Dividing a table into subsets of rows
5. . Vertical fragmentation means:
(A) Dividing a table into subsets of rows
(B) Dividing a table into subsets of columns
(C) Encrypting columns
(D) Compressing columns
6. . Replication in distributed databases refers to:
(A) Encrypting tables
(B) Storing copies of data at multiple sites for reliability and availability
(C) Compressing tables
(D) Deleting old records
7. . Data allocation refers to:
(A) Deleting old data
(B) Compressing tables
(C) Encrypting tables
(D) Assigning fragments of data to specific sites in a distributed system
8. . Advantages of distributed databases include:
(A) Improved reliability, availability, performance, and scalability
(B) Compressed data only
(C) Encrypted data only
(D) Automatic deletion of old records
9. . Disadvantages of distributed databases include:
(A) Complex design, high cost, and network dependency
(B) Only encryption issues
(C) Only compression issues
(D) Automatic deletion issues
10. . Transparency in distributed databases includes:
(A) Compression transparency only
(B) Encryption transparency only
(C) Location, replication, fragmentation, and concurrency transparency
(D) Backup transparency only
11. . Location transparency means:
(A) Data is encrypted
(B) Users do not need to know the physical location of data
(C) Data is compressed
(D) Data is deleted automatically
12. . Replication transparency means:
(A) Data is backed up
(B) Data is compressed
(C) Data is encrypted
(D) Users are unaware of multiple copies of data
13. . Fragmentation transparency means:
(A) Data is compressed
(B) Users can access data without knowing how it is fragmented
(C) Data is encrypted
(D) Data is deleted automatically
14. . Concurrency control in distributed databases ensures:
(A) Encryption of data
(B) Compression of data
(C) Correct execution of concurrent transactions across multiple sites
(D) Backup of data only
15. . Distributed deadlock occurs when:
(A) Backups fail
(B) Tables are compressed
(C) Data is encrypted
(D) Transactions at different sites wait indefinitely for resources held by each other
16. . Two-phase commit protocol in distributed databases is used to:
(A) Ensure all sites agree to commit a transaction or abort it
(B) Compress tables
(C) Encrypt tables
(D) Delete old records
17. . Global query optimization in distributed databases aims to:
(A) Compress data
(B) Minimize overall query execution cost across all sites
(C) Encrypt data
(D) Delete old records
18. . Advantages of replication include:
(A) Encryption only
(B) Compression only
(C) Increased reliability and faster local access
(D) Automatic deletion
19. . Challenges of distributed databases include:
(A) Network delays, consistency maintenance, deadlocks, and recovery
(B) Only compression issues
(C) Only encryption issues
(D) Backup issues only
20. . The main purpose of distributed databases is to:
(A) Encrypt data
(B) Compress data
(C) Provide efficient, reliable, and transparent access to data across multiple sites
(D) Delete old records automatically