261. What is database sharding?
- a) Horizontal partitioning of data across multiple servers
- b) Vertical partitioning of columns
- c) Replicating entire databases
- d) Compressing database files
Answer: A - Sharding distributes rows across nodes based on a shard key to scale write throughput.
262. What is a compensating transaction?
- a) A transaction that undoes the effects of a previous transaction
- b) A transaction that compensates for system failures
- c) A read-only transaction
- d) A transaction with adjusted isolation levels
Answer: A - Used in sagas to reverse committed steps when later steps fail in long-running processes.
263. What is the purpose of database attribute-based access control (ABAC)?
- a) Granular permissions based on user/object attributes and environmental conditions
- b) Controlling access to table columns
- c) A type of row-level security
- d) Encrypting database attributes
Answer: A - ABAC evaluates multiple attributes (e.g., department + time + location) for dynamic access decisions.
264. What is data virtualization?
- a) Abstracting multiple data sources as a single logical database
- b) Creating virtual database backups
- c) Simulating database workloads
- d) A type of in-memory database
Answer: A - Virtualization layers like Denodo provide unified querying without physical data movement.
265. What is lattice-based cryptography in database security?
- a) Post-quantum encryption resistant to Shor's algorithm attacks
- b) A type of column-level encryption
- c) Encrypting database schema structures
- d) A network encryption protocol
Answer: A - Lattice crypto provides quantum-resistant protection for sensitive data at rest.
266. What is database elastic scaling?
- a) Automatically adding/removing resources based on workload
- b) Stretching storage capacity
- c) A type of data compression
- d) Scaling only vertically
Answer: A - Cloud databases like CosmosDB scale out/in seamlessly with demand fluctuations.
267. What is a nested transaction?
- a) A transaction containing sub-transactions with partial rollback capability
- b) A transaction within a stored procedure
- c> A recursive transaction
- d> A transaction with multiple isolation levels
Answer: A - Nested transactions allow committing/rolling back sub-units independently within a parent transaction.
268. What is database dynamic data masking?
- a> Real-time obfuscation of sensitive data based on user permissions
- b> Encrypting data in motion
- c> A type of data compression
- d> Randomizing database IDs
Answer: A - Masking (e.g., showing only XX-XX-1234 for SSNs) protects data without changing stored values.
269. What is a data fabric architecture?
- a> Unified data management across hybrid/multi-cloud environments
- b> A type of database clustering
- c> Physical storage infrastructure
- d> A network topology for databases
Answer: A - Data fabrics provide consistent access, security, and governance across distributed data sources.
270. What is homomorphic encryption for databases?
- a> Performing computations on encrypted data without decryption
- b> Encrypting identical data the same way
- c> A type of transparent encryption
- d> Encrypting database structures
Answer: A - Allows querying encrypted data while preserving confidentiality.
271. What is database read replicas auto-scaling?
- a> Automatically adding read-only copies during peak loads
- b> Scaling replica sizes
- c> Adjusting replica synchronization
- d> A type of sharding
Answer: A - Cloud databases like Amazon Aurora can spawn temporary replicas for burst read capacity.
272. What is a saga pattern in distributed transactions?
- a> Sequence of local transactions with compensating actions on failure
- b> A long-running database transaction
- c> A type of two-phase commit
- d> A transaction logging method
Answer: A - Sagas maintain data consistency across services without distributed locks.
273. What is database zero-trust security?
- a> Verify explicitly, assume breach security model
- b> No authentication required
- c> A type of encryption
- d> Open access within perimeter
Answer: A - Continuously validates identities and enforces least-privilege access.
274. What is a logical data warehouse?
- a> Virtual integration layer over disparate sources
- b> A data warehouse design pattern
- c> A temporary staging warehouse
- d> A read-optimized database
Answer: A - Combines real-time query federation with cached performance optimizations.
275. What is post-quantum database cryptography?
- a> Algorithms resistant to quantum computing attacks
- b> Encrypting quantum data
- c> A type of quantum database
- d> Database encryption using qubits
Answer: A - Includes lattice-based, hash-based, and multivariate cryptographic schemes.
276. What is database write amplification?
- a> Extra writes caused by storage internals (e.g., SSDs, LSM trees)
- b> Replicating writes to multiple nodes
- c> A type of data corruption
- d> Writing redundant copies for safety
Answer: A - A key consideration for SSD lifespan and write-heavy workloads.
277. What is an out-of-band management interface for databases?
- a> Dedicated secure channel for administration separate from data plane
- b> External management tools
- c> A type of API gateway
- d> Remote database access
Answer: A - Provides emergency access when primary networks are unavailable.
278. What is database cold tier storage?
- a> Low-cost storage for rarely accessed data
- b> Offline backup storage
- c> A type of in-memory database
- d> Uncompressed database storage
Answer: A - Services like Azure Blob Storage Archive offer cents-per-GB retention.
279. What is database confidential computing?
- a> Processing data in hardware-protected memory enclaves
- b> Encrypting confidential columns
- c> A type of access control
- d> Secure database configuration
Answer: A - Technologies like Intel SGX protect data in use from cloud providers.
280. What is database chaos engineering?
- a> Intentional failure injection to improve resilience
- b> Random query generation
- c> A type of data corruption
- d> Stress testing databases
Answer: A - Proactively tests recovery from network partitions, node failures, etc.