How to Join two tables in Hbase

Question

Problem:

I am new to Hbase and I came across a situation where I need to join two tables.
Let us suppose I have Employee table and Department table both are created in Hbase. By reading Hbase in action , I got to know that we cannot join tables in Hbase.

Solution:

I found out a solution that by writing MapReduce Code using Hbase classes and Interfaces we can achieve this task.

Also if someone can help me with the coding that would be very helpful

Solution 1

The easiest way would be to load your HBase tables into Hive or Impala and perform a SQL join with those tools.

Solution 2

You should look at this jira issue in apache. You should use MultiTableInputFormat. https://issues.apache.org/jira/browse/HBASE-3996

See also: how to join tables in hbase

Solution 3

Using Hive or Impala is costly when data is to large and we face issue like Hbase kill(region server Down) . so it is convenient when data is small but not for large Data. In mapreduce take Hbase table object to take one table and by extending tablemapper use 2nd table. By this way you can join 2 tables.