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 …

Avro Data Types

This article explains the supported Data Types by Avro. Avro currently supports the follow Primitive Types: More details can be found on AVRO’s Apache documentation page. If you intend to create a column with TINYINT or SMALLINT for a AVRO table, you will get Undefined name: “TINYINT” error in CDH5.4.x, …