Tez

The following Hive statements will be transformed into four dependent MR jobs, their running process is shown in the figure, and the use of Tez can greatly simplify the calculation process

SELECT a.state, COUNT(*), AVERAGE(c.price)
  FROM a
  JOIN b ON(a.id = b.id)
  JOIN c ON(a.itemId = c.itemId)
  GROUP BY a.state