1) "Big Data" does not have a crystal clear, black and white definition.
It is generally characterized as being the processing and management of an amount and type of data that makes a specific workload on that data slow and/or expensive.
- Most commonly, Big Data involves processing and management of unstructured data of large volume and the typical technology used to store/process it is Hadoop, However, on occasion a NoSQL database will also deal with unstructured data.
- Big Data is also seen often in the form of simple, semi-structured data of both large volume and/or large velocity and the typical technology used to store/process it is a NoSQL database. However, on occasion Hadoop will also deal with semi-structured data of large volume.
- In some cases, Big Data is seen in the form of highly connected data that will be manipulated by advanced algorithms that will need to touch a lot of the data and the typical technology used to store/process it is a Graph type of NoSQL database.
2) NoSQL is a category of database technologies most often dealing with the issues as outlined in bullet 2 above. The Oracle NoSQL Database is oracle's product in the NoSQL category of database technologies. It does NOT store relational data. When using NoSQL relations between the data must be managed within the application code.
3) Hadoop and NoSQL booth manage Big Data, but different aspects as discussed in (1) above. Hadoop is a batch based, slow processing data technology, but the "slow" is relative because it can process very large amounts of data, so minutes is commonly seen as fast. NoSQL is a near real-time data processing technology and typically deals with Big Data where access times are in the single digit millisecond range.
Hope this helps,
Thanks for the information. I'm still a bit confused but no problem. Atleast I got some idea.
I'm having experience in PL/SQL Development. Now I am planning to learn Bigdata technology. Please suggest me whether it is more relavant to learn Hadoop or NOSQL for a pure Oracle DB proffessional.
NoSQL is a distributed database (with indexing and schemas). From a database perspective, NoSQL is a good place for you to get started. Hadoop is a distributed processing framework, rather than a database. If you're looking to leverage your database skills, then I would suggest starting with NoSQL.
Oracle Press recently published the "Oracle Big Data Handbook" which is a comprehensive overview of Oracle's Big Data technology product suite. I would start there. You can find the book on Oracle Press or Amazon or Barnes & Noble.
I hope that this helps.