NSCT – Query Processing & Optimization MCQs 20 min Score: 0 Attempted: 0/20 Subscribe 1. . Query processing in DBMS refers to: (A) The steps involved in converting a high-level query into an efficient execution plan (B) Compressing tables (C) Encrypting data (D) Deleting old recordsShow All Answers 2. . The main goal of query optimization is to: (A) Compress tables (B) Minimize resource usage and execution time (C) Encrypt tables (D) Delete old records 3. . Query evaluation plan is: (A) A sequence of operations that produces the result of a query (B) A backup file (C) Compressed table (D) Encrypted data 4. . Logical query optimization involves: (A) Transforming a query into an equivalent but more efficient form (B) Encrypting the query (C) Compressing the query (D) Deleting old data 5. . Physical query optimization involves: (A) Selecting the best algorithm and access paths to execute the query (B) Encrypting tables (C) Compressing tables (D) Deleting old records 6. . Relational algebra plays a key role in: (A) Deleting old data (B) Encrypting tables (C) Compressing tables (D) Query optimization by representing queries as algebraic expressions 7. . Cost-based query optimization selects a query plan based on: (A) Compressed data (B) Estimated cost in terms of I/O, CPU, and memory usage (C) Encrypted data (D) Backup frequency 8. . Heuristic query optimization uses: (A) Cost estimation (B) Rules of thumb like pushing selections/projections down (C) Compression techniques (D) Encryption techniques 9. . Join algorithms include: (A) Compression join (B) Nested-loop join, Sort-merge join, Hash join (C) Encryption join (D) Backup join 10. . Nested-loop join is suitable when: (A) Data is encrypted (B) Both relations are very large only (C) One relation is small and indexes are available on the other relation (D) Data is compressed 11. . Sort-merge join is efficient when: (A) Data is encrypted (B) Both relations are already sorted or can be sorted efficiently (C) Data is compressed (D) Only small relations exist 12. . Hash join is efficient when: (A) Data is compressed (B) Data is encrypted (C) Relations are large and hash tables can fit in memory (D) Only small relations exist 13. . Selection operation in query processing refers to: (A) Choosing columns (B) Choosing rows that satisfy a given condition (C) Compressing tables (D) Encrypting tables 14. . Projection operation in query processing refers to: (A) Choosing rows (B) Choosing specific columns from a table (C) Compressing tables (D) Encrypting tables 15. . Pipelining in query execution allows: (A) Passing intermediate results directly to the next operation without storing on disk (B) Compressing intermediate results (C) Encrypting results (D) Backup of intermediate results 16. . Materialized views help query optimization by: (A) Encrypting tables (B) Storing precomputed results for faster retrieval (C) Compressing tables (D) Deleting old records 17. . Access paths in query optimization include: (A) Encryption only (B) Compression only (C) Table scan, index scan, and index range scan (D) Backup paths 18. . Query rewrite techniques involve: (A) Deleting old queries (B) Encrypting queries (C) Compressing queries (D) Rewriting queries for more efficient evaluation without changing the result 19. . Cost estimation for query optimization considers: (A) I/O operations, CPU usage, memory usage, and network costs (B) Compression ratio (C) Encryption overhead (D) Backup frequency 20. . The main goal of Query Processing & Optimization is to: (A) Encrypt data (B) Compress tables (C) Execute queries efficiently while minimizing resource usage (D) Delete old records
