Joining two tables in Hadoop MapReduce Join.

[#1]

Hello everyone.

I'm completely new in Hadoop Framework and I want to write a MapReduce program (HadoopJoin.java) that joins on x attribut between two tables R and S. The structure of the two tables is like :

R (tag : char, x : int, y : varchar(30)) and
S (tag : char, x : int, z : varchar(30))

For example we have for R table :

r 10 r-10-0
r 11 r-11-0
r 12 r-12-0
r 21 r-21-0

And for S table :

s 11 s-11-0
s 21 s-41-0
s 21 s-41-1
s 12 s-31-0
s 11 s-31-1

The result should look like :

r 11 r-11-0 s 11 s-11-0

etc.

Can anyone help me please ?

[#2]

Don't use Map Reduce anymore.

It's time to move to Spark or Flink.