SQL MCQs | Database Interview MCQ Questions and Answers

Test your knowledge of Database - [ SQL ] section with these interactive multiple-choice questions.

« First 9 10 11 12 Last »
« Previous Page Next Page »

181. Which encryption algorithm is quantum-resistant?

  • a) CRYSTALS-Kyber
  • b) AES-256
  • c) RSA-4096
  • d) SHA3-512
Answer: A - NIST-approved post-quantum cryptography (SQL Server 2025+).

182. What is a multi-model database?

  • a) Supports multiple data formats
  • b) Runs on multiple platforms
  • c) Uses various storage engines
  • d) Implements polyglot persistence
Answer: A - Handles relational, document, graph in one system (e.g., PostgreSQL with extensions).

183. Which feature automatically creates optimal indexes?

  • a) Automatic Indexing
  • b) Index Advisor
  • c) Query Store Hints
  • d) All of the above
Answer: D - Oracle/PostgreSQL/SQL Server offer variations of this feature.

184. What is predictive scaling in cloud databases?

  • a) Anticipates workload changes
  • b) Forecasts storage needs
  • c) Pre-warms caches
  • d) All of the above
Answer: D - Uses ML to adjust resources before demand spikes occur.

185. Which statement enables database DevOps?

  • a) CREATE DEPLOYMENT PIPELINE
  • b) ENABLE SCHEMA DRIFT DETECTION
  • c) SET UP DATABASE STATE COMPARE
  • d) All of the above
Answer: D - Tools like Azure DevOps and Flyway implement these concepts.

186. What is the purpose of the SQL VALIDATE() function?

  • a) Checks data integrity constraints
  • b) Verifies JSON/XML schemas
  • c) Tests permissions
  • d) All of the above
Answer: D - Implementation varies by DBMS (Oracle: VALIDATE_CONVERSION).

187. Which database offers vector similarity search?

  • a) PostgreSQL with pgvector
  • b) MongoDB Atlas
  • c) Azure Cosmos DB
  • d) All of the above
Answer: D - Enables AI/ML applications with embedding searches.

188. What is the purpose of the SQL TRACKING_HISTORY() function?

  • a) Shows change tracking details
  • b) Audits historical queries
  • c) Traces lineage
  • d) Logs performance metrics
Answer: A - Snowflake-specific function for change tracking metadata.

189. Which statement creates a database clone?

  • a) CREATE DATABASE...CLONE
  • b) MAKE DATABASE COPY
  • c) DUPLICATE DATABASE
  • d) REPLICATE SCHEMA
Answer: A - Snowflake/Oracle use zero-copy cloning syntax.

190. What is the purpose of the SQL EXECUTE IMMEDIATE statement?

  • a) Runs dynamic SQL
  • b) Prioritizes queries
  • c) Bypasses parsing
  • d) Skips permissions checks
Answer: A - Executes string-based SQL statements (Oracle/PLpgSQL).

191. Which database feature enables data mesh architectures?

  • a) Federated queries
  • b) Data sharing
  • c) Secure data products
  • d) All of the above
Answer: D - Snowflake/Databricks provide these capabilities.

192. What is the purpose of the SQL UNNEST() function?

  • a) Expands arrays into rows
  • b) Flattens JSON
  • c) Decompresses data
  • d) Splits strings
Answer: A - Converts array elements to relational format (BigQuery/PostgreSQL).

193. Which statement creates a data share?

  • a) CREATE SHARE
  • b) MAKE DATA SHARE
  • c) ENABLE SHARING
  • d) PUBLISH DATABASE
Answer: A - Snowflake syntax for secure cross-account data sharing.

194. What is the purpose of the SQL APPROX_TOP_K() function?

  • a) Estimates frequent values
  • b) Ranks top performers
  • c) Samples data
  • d) Calculates percentiles
Answer: A - Probabilistic algorithm for heavy hitters (BigQuery).

195. Which database provides built-in workload management?

  • a) Snowflake (Warehouses)
  • b) SQL Server (Resource Governor)
  • c) Oracle (Database Resource Manager)
  • d) All of the above
Answer: D - Allocate CPU/memory to different query classes.

196. What is the purpose of the SQL SESSION_CONTEXT() function?

  • a) Accesses key-value session variables
  • b) Shows connection details
  • c) Tracks query history
  • d) Manages transactions
Answer: A - SQL Server's sp_set_session_context companion.

197. Which statement enables result caching?

  • a) ALTER SYSTEM SET RESULT_CACHE_MODE
  • b) ENABLE QUERY CACHING
  • c) CREATE CACHE POLICY
  • d) SET CACHE RESULTS
Answer: A - Oracle syntax for reusing identical query results.

198. What is the purpose of the SQL ML.PREDICT() function?

  • a) Applies machine learning models
  • b) Forecasts trends
  • c) Scores data
  • d) All of the above
Answer: D - BigQuery ML and SQL Server ML Services feature.

199. Which database offers automated anomaly detection?

  • a) Amazon Aurora ML
  • b) Azure SQL Anomaly Detection
  • c) Oracle Database Insights
  • d) All of the above
Answer: D - Identify unusual patterns in query performance/data values.

200. What is the purpose of the SQL DATABASE_REFRESH() procedure?

  • a) Updates development databases from production
  • b) Reloads cached data
  • c) Synchronizes replicas
  • d) Rebuilds indexes
Answer: A - Snowflake's stored procedure for test data refresh.
« First 9 10 11 12 Last »
« Previous Page Next Page »

SQL MCQs - Master Database Concepts from Basic to Advanced | PCBooks

🚀 Want to master SQL for interviews and exams? PCBooks offers the most comprehensive free SQL MCQ bank covering queries, joins, subqueries, and database optimization. Perfect for:

📊 SQL Query & Database Design MCQs

👉 SELECT, INSERT, UPDATE, DELETE command practice
👉 INNER, LEFT, RIGHT, FULL JOINs with real-world scenarios
👉 GROUP BY, HAVING, ORDER BY advanced usage
👉 Indexing strategies and query optimization techniques

📚 Free SQL Learning Path

🎯 Step-by-step tutorials on:
- Database normalization (1NF to BCNF)
- Stored procedures and functions
- Window functions (ROW_NUMBER, RANK, DENSE_RANK)
- Transaction control (COMMIT, ROLLBACK, SAVEPOINT)
🎯 Chapter-wise quizzes with detailed explanations
🎯 Downloadable SQL cheat sheets for quick revision

🚀 Practice SQL MCQs Now

Start Basic SQL MCQs →
MongoDB MCQs Practice →
Top 300 DBMS Concepts Interview Questions →


🏆 Trusted by 75,000+ learners for SQL certification and career growth!