SELECT * query triggered Map Only job under CDH5.5.1, but not from CDH5.3.x

This article explains why a map only job was launched while running a simple “SELECT * FROM <table>” query in CDH5.5.x, while same query did not need any MapReduce task in CDH5.3.x. After upgrading to CDH5.5.1, while running “SELECT * FROM <table>” query from Beeline, a map only job was …