Category: AG Quiz

This is a regular “data quiz”. Follow it on LinkedIn. Test your knowledge or learn something new. Today Question: ETL stands for: A) Extract, Transform, Load  B) Export, Transfer, Load  C) Extract, Transfer, Link  D) Encode, Transform, Load Correct Answer: A Explanation ETL (Extract, Transform, Load) is a fundamental process in data engineering and business intelligence that describes three key phases of data processing. The EXTRACT phase retrieves data from various…

This is a regular “data quiz”. Follow it on LinkedIn. Test your knowledge or learn something new. Today Question: Which method ensures ACID properties in a database? A) Indexing  B) Transactions  C) Cache  D) Sharding Correct Answer: B Explanation Transactions are the core mechanism that ensures ACID properties in databases. ACID stands for Atomicity, Consistency, Isolation, and Durability. Atomicity guarantees that a transaction is completed fully…

This is a regular “data quiz”. Follow it on LinkedIn. Test your knowledge or learn something new. Today Question: Which database is NoSQL? A) MySQL  B) PostgreSQL  C) MongoDB  D) SQLite Correct Answer: C Explanation MongoDB is one of the most popular NoSQL document databases that stores data in BSON (a binary form of JSON) documents instead of relational tables. NoSQL databases…

This is a regular “data quiz”. Follow it on LinkedIn. Test your knowledge or learn something new. Today Question: In PostgreSQL, the VACUUM command is used to: A) Data compression  B) Removing dead rows  C) Reindexing  D) Update Correct Answer: B Explanation The VACUUM command in PostgreSQL is used for database maintenance by removing dead rows created during UPDATE and DELETE operations. PostgreSQL uses MVCC (Multiversion Concurrency Control), which…

This is a regular “data quiz”. Follow it on LinkedIn. Test your knowledge or learn something new. Today Question: Which SQL data type stores JSON structures? A) TEXT  B) OBJECT  C) JSON  D) STRUCT Correct Answer: C Explanation The JSON data type is a relatively new feature of modern SQL databases that allows native storage and processing of JSON (JavaScript Object Notation) documents directly in…

This is a regular “data quiz”. Follow it on LinkedIn. Test your knowledge or learn something new. Today Question: Data normalization serves to: A) Increase redundancy  B) Remove duplicates  C) Speed up queries  D) Simplify JOINs Correct Answer: B Explanation Normalization is a fundamental principle of relational database design that aims to eliminate redundancy and ensure data consistency. The normalization process divides large tables into smaller, logically…

This is a regular “data quiz”. Follow it on LinkedIn. Test your knowledge or learn something new. Today Question: Which SQL command deletes a table along with its structure? A) DELETE  B) DROP  C) TRUNCATE  D) REMOVE Correct Answer: B Explanation The DROP command is one of the most destructive SQL commands, which completely removes a table from the database including its structure, data, indexes, triggers, and all…

This is a regular “data quiz”. Follow it on LinkedIn. Test your knowledge or learn something new. Today Question: What is the purpose of an index in a database? A) Increase write speed  B) Increase read speed  C) Reduce data size  D) Replace keys Correct Answer: B Explanation A database index is a data structure that significantly speeds up searching and reading data from tables. It works similarly to an index in a book –…

This is a regular “data quiz”. Follow it on LinkedIn. Test your knowledge or learn something new. Today Question: Which type of JOIN returns all rows from the left table and matching ones from the right? A) INNER B) LEFT C) RIGHT D) FULL Correct Answer: B Explanation LEFT JOIN is one of the most…