Why spark is used in Hadoop?

Related questions

1. What is spark language used for?
2. What is spark in Hadoop?
3. Why do we need spark?
4. What is faster than Apache spark?
5. How do I start learning spark?
6. Do I need Scala for spark?
7. Why should I learn spark?
8. How long does it take to learn spark?
9. How is Hadoop different from spark?

Tags

1. #hadoop
2. #several
3. #using
4. #spark
5. #apache
6. #concept
7. #level
8. #files
9. #dataset
10. #memory
11. #across
12. #parallel
13. #writes
14. #reads
15. #difference
16. #project
17. #cluster
18. #processing
19. #works
20. #distributed
21. #focused
22. #biggest
23. #whereas
24. #processes
25. #resilient
26. #known