Hadoop : What it is meant to do What it is not

Hadoop's architecture

Hadoop was not designed for Enterprise Architecture , It was designed for Clustered Architecture.

so think in right context.

Hadoop is designed to run on a large number of machines that don’t share any memory or disks. That means you can buy a whole bunch of commodity servers, slap them in a rack, and run the Hadoop software on each one.

Hadoop is Not meant to

1. Replace RDBMs
2. do Transactions
3. Generally used with unstructured data , may be used with structured as well

Hadoop is meant to

1. Index building, pattern recognitions,
2. Creating recommendation engines, 
3. Sentiment analysis -- all situations where data is generated at a high volume, 
4. Read 1 TB file in minutes rather than hours

Hadoop Vs RDBMS

1. Hadoop can do interactive data but not same speed
2. Hadoop cant do ACID
3. Hadoop best to work with unstructured data , RDMS best to work with structured data