Data Processing Cheat Sheet 2026

The 30 highest-yield Data Processing facts, distilled from real exam questions. Print it, save it as a PDF, or study it here — free, no sign-up.

1. What is horizontal scaling in the context of big data systems? → Adding more machines to a cluster to increase processing capacity
2. Which technique replaces sensitive data with realistic but fictitious values to protect privacy? → Data masking
3. Which validation rule ensures a field contains only alphabetic characters? → Data type check
4. What is data consistency in data processing? → Data is the same across all systems and does not contradict itself
5. What is Apache Hive used for? → Querying and managing large datasets stored in Hadoop using a SQL-like interface
6. What is a stored procedure in a DBMS? → A precompiled set of SQL statements stored and executed on the database server
7. What does 'data accuracy' mean in data quality terms? → Data correctly represents the real-world values it is intended to model
8. What is the purpose of Apache NiFi in data pipelines? → Automating data flow between systems with a visual, drag-and-drop interface
9. What is a view in SQL? → A virtual table based on the result of a SELECT query
10. Inquiring about database-stored information is sometimes referred to as → Field
11. What is data aggregation in ETL transformation? → Combining multiple values into a single summary value such as a sum or average
12. What is the purpose of a staging area in ETL processing? → A temporary storage location where data is held between extraction and loading
13. What is a data pipeline? → A series of automated steps that move and transform data from source to destination
14. What does HDFS stand for? → Hadoop Distributed File System
15. What is a transaction in database processing? → A unit of work that is executed completely or not at all
16. What is the primary disadvantage of real-time stream processing compared to batch? → Higher system complexity and infrastructure cost to achieve low-latency guarantees
17. What does the SQL JOIN clause do? → Combines rows from two or more tables based on a related column
18. What is batch processing in data systems? → Collecting and processing large volumes of data at scheduled intervals
19. Which transformation converts data from one format to another, such as date formats? → Data conversion
20. What is stream processing in big data? → Continuously processing data as it arrives in real time
21. What is the purpose of database caching? → Storing frequently accessed data in fast memory to reduce retrieval time
22. Three commonly accepted classifications of confidentiality-related issues in database systems include all but → Accepting and initiating unwanted popups.
23. What is backpressure in stream processing systems? → A flow control mechanism where a slow consumer signals a fast producer to slow down
24. What is a lookup table used for in data validation? → To verify that a field value exists within a predefined list of valid options
25. Viruses can be acquired through → Cracked software
26. Which term describes data that is incorrect, incomplete, or inconsistent? → Dirty data
27. The software in question is an example of a database management system. → Microsoft Power Point
28. What is the purpose of data archiving? → Moving infrequently accessed data to lower-cost storage for long-term retention
29. What is timeliness as a data quality dimension? → Whether data is available and up-to-date when needed
30. Which technique detects whether two related fields contain logically consistent values? → Cross-field validation