Using Apache Hive

Abstract

Apache Hive is data warehouse framework for storing, managing and querying large data sets. The Hive query language HiveQL is a SQL-like language. Hive stores data in HDFS by default, and a Hive table may be used to define structure on the data. Hive supports two kinds of tables: managed tables and external tables. A managed table is managed by the Hive framework while an external table is not. When a managed table is deleted, the metadata and the table data are deleted. When a Hive external table is deleted, only the metadata is deleted, and the table data is not since the table data is not managed by the Hive framework. Hive makes use of a metastore to store metadata about Hive tables. A Hive metastore database is used for the metastore and is the Derby database by default. The metastore database may be run in embedded mode or remote mode; the default being embedded mode. In this chapter we shall use a Docker image to run Apache Hive in a Docker container.