Big Data is sets of data and it is so large or complex that traditional data processing application software’s inadequate to deal with them. It includes challenges like analysis, data creation, capture, search, storage, sharing, visualization, transfer, query, and information for privacy. Here We have listed the top 25 Big Data Interview Questions.
Big Data Interview Questions
1. What is Big Data?
- It describes the large volume of Data both Structured and Unstructured.
- The term Big Data refers to simply the use of predictive analytics, user behavior analytics, and other advanced data analytics methods.
- It is extract value from data and seldom to a particular size of the data set.
- The challenge includes capture, storage, search, sharing, transfer, analysis, and creation.
2. Which are the essential Hadoop Tools for the effective working of Big Data?
The effective Tools are as follows
- HBase
- HIVE
- Sqoop
- Pig
- ZooKeeper
- NOSQL
- Mahout
- Lucene/Solr
- Avro
- Oozie
- GIS tools
- Flume
3. What are the key steps in Big Data Solutions?
Key steps in Big Data Solutions
Ingesting Data, Storing Data (Data Modelling), and Processing data (Data wrangling, Data transformations, and querying data).
Ingesting Data
- RDBMsRelational Database Management Systems like Oracle, MySQL, etc.
- ERPs Enterprise Resource Planning (ERP) systems like SAP.
- CRMCustomer Relationships Management systems like Siebel, Salesforce, etc.
- Social Media feeds and log files.
- Flat files, docs, and images.
Storing Data
- Data Storage Formats
- Data Modelling
- Metadata management
- Multitenancy
4. Data Analysis Process?
Five steps of the Analysis Process
Step 1: Define Your Questions
Step 2: Set Clear Measurement Priorities
Step 3: Collect Data
Step 4: Analyse Data
Step 5: Interpret Results
5. What is Big Data Analysis?
- It is defined as the process of mining large structured/unstructured data sets.
- It helps to find out underlying patterns, and unfamiliar and other useful information within data leading to business benefits.
6. Name some Big Data Products?
- R
- Rattle
- Hadoop
- RHadoop
- Mahout
7. Where does Big Data come from?
There are three sources of Big Data
- Social Data: It comes from social media channels insights on consumer behavior.
- Machine Data: It consists of real-time data generated from sensors and weblogs. It tracks user behavior online.
- Transaction Data: It is generated by large retailers and B2B Companies frequent basis.
8. What is IBM’s simple explanation for Big Data’s four critical features?
Big Data features:
- Volume: Scale of Data
- Velocity: Analysis of streaming Data
- Variety: Different forms of Data
- Veracity: Uncertainly Of Data
9. How businesses could be benefitted from Big Data?
- Big data analysis helps the business to render real-time data.
- It can influence to make crucial decisions of the strategies and development of the company.
- Big data helps within a large scale to differentiate themselves in the competitive environment.
10. Where the Mappers Intermediate data will be stored?
- The mapper output is stored in the local file system of each individual mapper node.
- A temporary directory location can be set up in the configuration
- By the Hadoop administrator.
- The intermediate data is cleaned up after the Hadoop Job is completed.
11. Differentiate between Structured and Unstructured data?
| Structured Data | Unstructured Data |
| Basis algorithms | Old algorithms |
| Spreadsheet data from machine sensors | Human language |
| SQL | Windows explorer, Mac finder screen |
12. How are file systems checked in HDFS?
- The file system is used to control how data are stored and retrieved.
- Each file system has a different structure and logic properties of speed, security, flexibility, and size.
- Such kind of file system is designed in hardware. This file includes NTFS, UFS, XFS, and HDFS.
13. What is MapReduce?
- It is a core component, of the Apache Hadoop Software framework.
- It is a programming model and an associated implementation for processing and generating large data.
- This data sets with a parallel, and distributed algorithm on a cluster, each node of the cluster includes its own storage.
14. What is speculative execution?
- It is an optimization technique.
- The computer system performs some tasks that may not be actually needed.
- This approach is employed in a variety of areas, including branch prediction in pipelined processors, and optimistic concurrency control in database systems.
15. Pig Latin contains different relational operations; name them.
- group
- distinct
- join
- for each
- order by
- filters
- limit
16. Why are counters useful in Hadoop?
- The counter is an integral part of any Hadoop job.
- It is very useful to gather relevant statistics.
- A particular job consists of 150 node clusters with 150 mappers.
- Counters can be used for keeping a final count of all such records and presenting a single output.
17. What is the default block size in Hdfs?
The default block size in Hdfs is 64MB.
18. Which hardware configuration is most beneficial for Hadoop jobs?
- Dual processor core machines with 4/ 8 GB RAM
- ECC Memory conducting Hadoop Operations, cannot be considered to be low-end.
- It is useful for Hadoop users, and it does not deliver any checksum errors.
- The hardware configuration depends on the process and workflow needs of specific projects and it has customized.
19. What are the main distinctions between NAS and HDFS?
NAS
- The files reside on a single machine.
- It does not provide any reliability guarantees.
- It can store as much information as to be stored in one machine.
- All the data is stored on a single machine, all the clients must go to this machine to retrieve their data.
- It can overload the server if a large number of clients must be handled.
HDFS
- It is designed to store a very large amount of information.
- This requires spreading the data across a large number of machines. It also supports much larger file sizes than NFS.
- HDFS is optimized to provide streaming read performance; this comes at the expense of random seek times to arbitrary positions in files.
- Data will be written to the HDFS once and then read several times; updates to files after they have already been closed are not supported.
20. What are the industrial applications of big data?
- Banking And Securities
- Communication, Media & Entertainment
- Healthcare Providers
- Education
- Government
- Insurance
- Retail And Wholesale Sale
- Transportation
- Energy Utilities
21. How can you an application, if you run hive as a server?
ODBC Driver
It supports the ODBC Protocol
JDBC Driver
It supports the JDBC protocol
Thrift Client
It is utilized to make calls to all hive commands using programming languages such as PHP, Java, C++, Python, and Ruby.
22. What kind of Data Warehouse application is suitable for Hive?
- Fast response times are not required
- Relatively static data is analyzed
- The data is not changing rapidly
23. What is data serialization?
- Serialization is the way of converting object data to a byte data stream for transmission.
- Network across different nodes in a cluster / for persistent data storage.
24. How to debug the Hadoop code?
- By using counters
- By web interface provided by the Hadoop framework
25. What is metadata?
Metadata is the information about the Data stored in Data Nodes such as the location of the file, and the size of the file.