A) DISTINCT
B) UNIQUE
C) DIFFERENT
D) SEPARATE
Answer: A

302. The BETWEEN operator in SQL is used to:
A) Filter data within a range
B) Combine tables
C) Match patterns
D) None
Answer: A

303. The LIKE operator is used with:
A) Wildcards
B) Aggregates
C) Constraints
D) None
Answer: A

304. The wildcard symbol % represents:
A) Zero or more characters
B) Single character
C) Numeric data
D) None
Answer: A

305. The _ (underscore) wildcard in SQL represents:
A) A single character
B) Multiple characters
C) Numeric value
D) None
Answer: A

306. The ORDER BY clause sorts data by:
A) One or more columns
B) Only primary key
C) Random order
D) None
Answer: A

307. The default sorting order in SQL is:
A) Ascending
B) Descending
C) Random
D) None
Answer: A

308. To sort data in descending order, we use:
A) ORDER BY column DESC
B) ORDER BY column ASC
C) SORT BY column
D) None
Answer: A

309. Aggregate functions operate on:
A) Groups of rows
B) Individual cells
C) Columns only
D) None
Answer: A

310. COUNT(*) returns:
A) Number of rows in a table
B) Number of columns
C) Number of NULL values
D) None
Answer: A

311. AVG() function is used to calculate:
A) Average of numeric values
B) Total of all values
C) Number of values
D) None
Answer: A

312. SUM() function calculates:
A) Total sum of numeric column
B) Count of rows
C) Average
D) None
Answer: A

313. The MAX() function returns:
A) Largest value
B) Smallest value
C) Total sum
D) None
Answer: A

314. The MIN() function returns:
A) Smallest value
B) Average
C) Total
D) None
Answer: A

315. The GROUP BY clause is used to:
A) Group rows based on column values
B) Sort rows
C) Delete duplicates
D) None
Answer: A

316. HAVING clause is used to filter:
A) Groups created by GROUP BY
B) Individual rows
C) Joins only
D) None
Answer: A

317. The difference between WHERE and HAVING is:
A) WHERE filters rows; HAVING filters groups
B) Both filter rows
C) Both filter columns
D) None
Answer: A

318. Subqueries can be nested:
A) Within SELECT, INSERT, UPDATE, DELETE
B) Only in SELECT
C) Only in DELETE
D) None
Answer: A

319. A correlated subquery executes:
A) Once for each row of outer query
B) Only once
C) Randomly
D) None
Answer: A

320. A scalar subquery returns:
A) A single value
B) A table
C) Multiple rows
D) None
Answer: A

321. EXISTS operator returns TRUE if:
A) The subquery returns at least one row
B) All rows are NULL
C) Subquery fails
D) None
Answer: A

322. The IN operator checks:
A) If a value matches any value in a list
B) If value is numeric
C) If value exists in table name
D) None
Answer: A

323. A stored procedure is:
A) A precompiled collection of SQL statements
B) A database backup
C) A table
D) None
Answer: A

324. Stored procedures improve performance because:
A) They are compiled once and reused
B) They are interpreted every time
C) They skip execution
D) None
Answer: A

325. Stored procedures can accept:
A) Input and output parameters
B) Only output
C) Only input
D) None
Answer: A

326. The RETURN statement in a function is used to:
A) Return a single value
B) Return multiple rows
C) Commit a transaction
D) None
Answer: A

327. A trigger automatically executes:
A) In response to a specified database event
B) Manually by user
C) After a query runs
D) None
Answer: A

328. Triggers can be set for:
A) INSERT, UPDATE, DELETE operations
B) SELECT only
C) COMMIT
D) None
Answer: A

329. A BEFORE trigger executes:
A) Before the event occurs
B) After event
C) Randomly
D) None
Answer: A

330. An AFTER trigger executes:
A) After the triggering event
B) Before event
C) Only once per table
D) None
Answer: A

331. Mutating table error occurs when:
A) A trigger modifies its own table
B) Table has no key
C) Database is locked
D) None
Answer: A

332. A cursor is used to:
A) Fetch multiple rows one at a time
B) Update metadata
C) Compile queries
D) None
Answer: A

333. Implicit cursors are created:
A) Automatically for single-row queries
B) Manually by user
C) For DDL statements
D) None
Answer: A

334. Explicit cursors must be:
A) Declared and controlled manually
B) Auto-handled
C) Closed by DBMS
D) None
Answer: A

335. The %NOTFOUND attribute returns TRUE when:
A) No more rows to fetch
B) Row fetched successfully
C) Cursor closed
D) None
Answer: A

336. COMMIT permanently:
A) Saves changes made in a transaction
B) Undoes changes
C) Starts a rollback
D) None
Answer: A

337. ROLLBACK reverses:
A) Uncommitted changes
B) Committed changes
C) Indexes
D) None
Answer: A

338. SAVEPOINT allows:
A) Partial rollback to a specific point
B) Full rollback only
C) Backup
D) None
Answer: A

339. Database recovery is needed after:
A) System crash or failure
B) Normal shutdown
C) Successful transaction
D) None
Answer: A

340. REDO operation is used to:
A) Reapply committed transactions
B) Undo failed transactions
C) Remove logs
D) None
Answer: A

341. UNDO operation is used to:
A) Rollback uncommitted transactions
B) Reapply transactions
C) Delete tables
D) None
Answer: A

342. Deferred update technique applies updates:
A) After transaction commit
B) Immediately
C) During execution
D) None
Answer: A

343. Immediate update technique applies updates:
A) As soon as operations occur
B) After commit
C) On restart
D) None
Answer: A

344. Checkpoints help in:
A) Reducing recovery time after crash
B) Index creation
C) Schema updates
D) None
Answer: A

345. Shadow paging is used for:
A) Recovery without log
B) Transaction concurrency
C) Query optimization
D) None
Answer: A

346. RAID in databases stands for:
A) Redundant Array of Independent Disks
B) Rapid Access Integrated Database
C) Random Access Indexed Disk
D) None
Answer: A

347. RAID improves:
A) Performance and fault tolerance
B) Query language
C) Backup speed only
D) None
Answer: A

348. In RAID 1, data is:
A) Mirrored across disks
B) Striped
C) Parity-encoded
D) None
Answer: A

349. In RAID 5, data is:
A) Striped with distributed parity
B) Mirrored
C) Randomly stored
D) None
Answer: A

350. Database design aims to:
A) Minimize redundancy and ensure consistency
B) Increase duplication
C) Slow down access
D) None
Answer: A

351. A database system that distributes data across multiple locations is called:
A) Distributed Database System
B) Centralized Database
C) File System
D) None
Answer: A

352. The main goal of a distributed database is:
A) Data transparency and reliability
B) Data duplication
C) Reduced security
D) None
Answer: A

353. Fragmentation in a distributed database refers to:
A) Splitting a database into smaller parts
B) Duplicating data
C) Compressing files
D) None
Answer: A

354. Replication in a distributed database means:
A) Copying data across multiple sites
B) Deleting old data
C) Encrypting data
D) None
Answer: A

355. The two types of replication are:
A) Synchronous and Asynchronous
B) Manual and Automatic
C) Serial and Parallel
D) None
Answer: A

356. Data transparency ensures that users:
A) Do not need to know data location
B) Must specify location
C) Manually move data
D) None
Answer: A

357. Homogeneous distributed databases use:
A) Same DBMS at all sites
B) Different DBMS
C) Flat files
D) None
Answer: A

358. Heterogeneous distributed databases use:
A) Different DBMS systems
B) Same DBMS
C) Only cloud storage
D) None
Answer: A

359. The coordinator site in distributed databases:
A) Manages global transactions
B) Stores only metadata
C) Stores only backup
D) None
Answer: A

360. The global schema represents:
A) Overall logical view of the distributed database
B) Local database structure
C) Physical storage view
D) None
Answer: A

361. Local schema defines:
A) Database structure at each site
B) Global mapping
C) Network schema
D) None
Answer: A

362. Data replication improves:
A) Reliability and availability
B) Query execution time
C) Both A and B
D) None
Answer: C

363. A major disadvantage of replication is:
A) Data inconsistency
B) Data loss
C) Faster access
D) None
Answer: A

364. Two-phase commit protocol ensures:
A) Atomicity in distributed transactions
B) Backup creation
C) Query optimization
D) None
Answer: A

365. In phase one of 2PC, the coordinator:
A) Asks all sites to prepare to commit
B) Commits directly
C) Rolls back
D) None
Answer: A

366. In phase two of 2PC, the coordinator:
A) Decides to commit or abort
B) Collects data
C) Updates schema
D) None
Answer: A

367. A NoSQL database is primarily:
A) Non-relational
B) Relational
C) Based on tables
D) None
Answer: A

368. NoSQL databases are designed for:
A) Handling large volumes of unstructured data
B) Traditional transactions
C) Only numeric data
D) None
Answer: A

369. Which of the following is a type of NoSQL database?
A) Document-based
B) Key-Value
C) Graph
D) All of the above
Answer: D

370. MongoDB is an example of:
A) Document-based NoSQL database
B) Relational database
C) Graph database
D) None
Answer: A

371. Cassandra is a:
A) Column-oriented NoSQL database
B) Document-based database
C) Key-value store
D) None
Answer: A

372. Redis is an example of:
A) Key-value store
B) Document store
C) Column-family store
D) None
Answer: A

373. Neo4j is an example of:
A) Graph-based database
B) Key-value store
C) Document store
D) None
Answer: A

374. BASE properties in NoSQL stand for:
A) Basically Available, Soft state, Eventual consistency
B) Binary Access, State, Execution
C) Backup, Access, Security
D) None
Answer: A

375. Unlike ACID, BASE focuses on:
A) Scalability and availability
B) Strict consistency
C) Transactions
D) None
Answer: A

376. Sharding in databases means:
A) Partitioning data horizontally
B) Replicating data vertically
C) Compressing tables
D) None
Answer: A

377. Indexing in a database helps to:
A) Speed up data retrieval
B) Slow down updates
C) Store backup
D) None
Answer: A

378. The structure used in database indexing is often a:
A) B-Tree or B+ Tree
B) Binary Search Tree
C) Linked List
D) None
Answer: A

379. A clustered index:
A) Determines the physical order of data
B) Is created separately
C) Does not affect storage
D) None
Answer: A

380. A non-clustered index:
A) Maintains a separate structure for data references
B) Changes physical order
C) Deletes records
D) None
Answer: A

381. Dense index stores entries for:
A) Every search key value
B) Only some keys
C) One per block
D) None
Answer: A

382. Sparse index stores entries for:
A) One record per block
B) Every record
C) Every column
D) None
Answer: A

383. A hash index is best for:
A) Exact match queries
B) Range queries
C) Grouping
D) None
Answer: A

384. A B+ Tree index supports:
A) Both exact and range searches
B) Only equality checks
C) Only sorting
D) None
Answer: A

385. File organization refers to:
A) The way records are stored on disk
B) The schema design
C) SQL query arrangement
D) None
Answer: A

386. Sequential file organization stores data:
A) In sorted order by key
B) Randomly
C) By hash
D) None
Answer: A

387. Heap file organization stores records:
A) In no particular order
B) In sorted order
C) In index order
D) None
Answer: A

388. Hash file organization uses:
A) Hash function to determine storage location
B) Sorting method
C) Linked list
D) None
Answer: A

389. An overflow bucket is used in:
A) Hash file organization
B) Sequential files
C) Index files
D) None
Answer: A

390. Primary index is created on:
A) Primary key field
B) Foreign key
C) Non-key field
D) None
Answer: A

391. Secondary index is created on:
A) Non-primary key fields
B) Only primary key
C) Clustered data
D) None
Answer: A

392. Multilevel indexing is used to:
A) Reduce search time for large files
B) Increase redundancy
C) Backup data
D) None
Answer: A

393. The top-level index in a multilevel index is called:
A) Master index
B) Secondary index
C) Dense index
D) None
Answer: A

394. Query optimization refers to:
A) Choosing the most efficient query execution plan
B) Writing long queries
C) Using subqueries only
D) None
Answer: A

395. Cost-based optimization estimates:
A) CPU, I/O, and memory costs
B) Only query length
C) Syntax errors
D) None
Answer: A

396. Heuristic optimization uses:
A) Rules and transformations
B) Cost metrics
C) Random plans
D) None
Answer: A

397. A query execution plan is:
A) The strategy used by DBMS to execute a query
B) User’s SQL query
C) Schema diagram
D) None
Answer: A

398. Query decomposition breaks a query into:
A) Smaller subqueries
B) Index tables
C) File blocks
D) None
Answer: A

399. A materialized view stores:
A) Precomputed query results
B) Only SQL syntax
C) Raw data
D) None
Answer: A

400. The advantage of a materialized view is:
A) Faster query performance for complex joins and aggregates
B) Slower updates
C) Increased redundancy
D) None
Answer: A