Schema Registry, SAM, Druid, and Superset require a relational data store to store metadata. You can use either MySQL or Postgres for this. This chapter describes how to install either MySQL or Postgres, and how create a databases for SAM and Registry. If you are installing on an existing HDP cluster by using Superset, you can skip the installation instructions, because MySQL was installed with Druid. In this case, configure the databases.

	Note
	You should install either Postgres or MySQL; both are not necessary. It is recommended that you use MySQL.

	Warning
	If you are installing Postgres, you must install Postgres 9.5 or later for SAM and Schema Registry. Ambari does not install Postgres 9.5, so you must perform a manual Postgres installation.

Installing and Configuring MySQL

Installing and Configuring Postgres