Advantages of MongoDB over RDBMS

The Advantages of MongoDB over RDBMS are

• No schema migrations. Since MongoDB is schema-free, your code defines your schema.
• Number of fields, content and size of the document can be different from one document to another.
• Tuning using indexes

• Ease of scale-out: MongoDB is easy to scale by adding commodity hardware

“ VoltDB ” - NewSQL DBMS For High Velocity Applications

VoltDB is a high performance scalable RDBMS and NewSQL Database primarily for Big Data, high velocity OLTP and Real-time analytics designed by Michael Stonebraker, Sam Madden, and Daniel Abadi.

It was one of the NewSQL databases first introduced as open source product in 2010.Demand for high scale and in memory databases(which means it depends mainly on main memory for storage) in the market has shaped great aperture for VoltDB.

Differences between Datawarehouse schema and RDBMS schema?

RDBMS Schema	DWH Schema
Used in OLTP system like banking	Used for OLAP systems
Its Normalized using either of the normal forms	Its De normalized
Its difficult to understand the tables and understand in User perspective	Easy to understand and mainly used for data analysis and extracting the data.