title: How to process skewed data using Hive?
body: <p>I am doing join operation in hive. But when reducer reaches 99% reducer gets stuck.</p>
  
  <p>Then i identified that there is skew data in table. 
  Ex. In table A there is 1 million data and table B has 10k only.In table A joining column has 80% values are same and rest is other. So hive reducer stuck at that value.</p>
  
  <p>Here is my query :</p>
  
  <pre><code>INSERT INTO TABLE xyz SELECT m.name, m.country, m.user_type, m.category FROM A m JOIN category n ON (m.name = n.name) where country=2 GROUP BY m.name, m.country, m.user_type, m.category;
  </code></pre>
  
  <p>So please suggest possible solution. How can i process join operation on this kind of data.</p>