This question seems to be very easy, but in an interview these simple questions matter a lot. So, here is how you can answer the very question:
RDBMS Hadoop
Data Types RDBMS relies on the structured data and the schema of the data is always known. Any kind of data can be stored into Hadoop i.e. Be it structured, unstructured or semi-structured.
Processing RDBMS provides limited or no processing capabilities. Hadoop allows us to process the data which is distributed across the cluster in a parallel fashion.
Schema on Read Vs. Write RDBMS is based on ‘schema on write’ where schema validation is done before loading the data. On the contrary, Hadoop follows the schema on read policy.
Read/Write Speed In RDBMS, reads are fast because the schema of the data is already known. The writes are fast in HDFS because no schema validation happens during HDFS write.
Cost Licensed software, therefore, I have to pay for the software. Hadoop is an open source framework. So, I don’t need to pay for the software.
Best Fit Use Case RDBMS is used for OLTP (Online Trasanctional Processing) system. Hadoop is used for Data discovery, data analytics or OLAP system.
