Initials of HADOOP

1. Hadoop is an open source project of the Apache Foundation.
2. It is a framework written in Java originally developed by Doug Cutting who named it after his son's toy elephant.
3. Hadoop uses Google’s MapReduce and Google File System technologies as its foundation.It is optimized to handle massive quantities of data which could be structured, unstructured or semi-structured, using commodity hardware,that is, relatively inexpensive computers. 
4. Hadoop replicates its data across multiple computers, so that if one goes down, the data is processed on one of the replicated computers. It is a batch operation handling massive quantities of data, so the response time is not immediate. 
5. Hadoop is not good to process transactions due to its lack random access. 
6. Hadoop is not suitable for OnLine Transaction Processing workloads where data is randomly accessed on structured data like a relational database. 
7. Hadoop is not suitable for OnLine Analytical Processing or Decision Support System workloads where data is sequentially accessed on structured data like a relational database, to generate reports that provide business intelligence. 
8. It is NOT a replacement for a relational database system.