Hive database

The database in Hive describes a collection of tables that are used for a similar purpose or belong to the same groups. If the database is not specified, the default database is used. Whenever a new database is created, Hive creates a directory for each database at /user/hive/warehouse, defined in hive.metastore.warehouse.dir. For example, the myhivebook database is located at /user/hive/datawarehouse/myhivebook.db. However, the default database doesn't have its own directory. The following is the core DDL for Hive databases:

• Create the database without checking whether the database already exists:

  jdbc:hive2://> CREATE DATABASE myhivebook;
  

• Create the database and check whether the database already exists:

  jdbc:hive2://> CREATE DATABASE IF NOT EXISTS myhivebook;
  

• Create the database with location, comments, and metadata information:

  jdbc:hive2://> CREATE DATABASE IF NOT EXISTS myhivebook
  . . . . . . .> COMMENT 'hive database demo'
  . . . . . . .> LOCATION '/hdfs/directory...