Limitation of RDBMS – Seek Time

Seek time is improving slower than the transfer rate.

Typically is 90’s a drive would be of 1 GB and transfer speed would be 4.5 MB/s

Thus time taken to read the drive = Total Memory / Speed
= 1000 / 4.5 ~ 222 sec ~ 4 min.

Typically scenario now-a-days is 1TB memory and transfer speed of 100 MB/s

Thus time taken to read the drive = Total memory / speed
= 1,000,000 / 100 ~ 10,000 sec ~ 166 min
= ~2.8 hr.


Advantage of Parallelism

Suppose that the 1 TB data is distributed over 50 nodes on a cluster with 1/50 th of the data on each node.

The read time will be 1/50 th of the 1 TB red would be close to 3.5 min.

Hadoop maintains replicas of the copies and this failures do not effect the integrity of data.

Naveen P.N

12+ years of experience in IT with vast experience in executing complex projects using Java, Micro Services , Big Data and Cloud Platforms. I found NPN Training Pvt Ltd a India based startup to provide high quality training for IT professionals. I have trained more than 3000+ IT professionals and helped them to succeed in their career in different technologies. I am very passionate about Technology and Training. I have spent 12 years at Siemens, Yahoo, Amazon and Cisco, developing and managing technology.