Enable passwordless sudoers for a user

We can add following line in /etc/sudoers to enable the user to be passwordless login from other machines.


<username>  ALL=(ALL:ALL) NOPASSWD: ALL

Comparison between RDBMS and Map-Reduce

	RDBMS	Map-Reduce
Scalability	Scale UP	Scale Out
Data Size	GB	PB and more
Read/Write	Batch and Interactive	Batch
Update Type	Write many Read many	Write once Read many
Integrity	High	Low
Structure	Structural data/ Schema first Write later	Non Structural data/ Write first Schema later
Query	SQL	No SQL and SQL support too with add on tools
Response time	Faster for Less data/ slow once size increases	Faster for more data in comparison
Note: Slowly with the new sub projects being developed for Hadoop this gap is being filled up as people are developing an abstract layer on top of Map-Reduce and YARN frameworks which takes SQL and in turn convert it to Map-Reduce/Yarn.