Helpful guidelines

How do you describe a table in Hive?

How do you describe a table in Hive?

There are three ways to describe a table in Hive.

  1. To see table primary info of Hive table, use describe table_name; command.
  2. To see more detailed information about the table, use describe extended table_name; command.
  3. To see code in a clean manner use describe formatted table_name; command to see all information.

What is Derby database in Hive?

Derby is also an open-source relational database tool that comes with a hive(by default) and is owned by apache. Nowadays, From an industry perspective, the derby is used for only testing purposes, and for deployment purposes, Metastore of MySql is used. Prerequisite: Hadoop should be pre-installed.

How do I view tables in Hive database?

Switch to the Hive schema and issue the SHOW TABLES command to see the Hive tables that exist. Switch to the HBase schema and issue the SHOW TABLES command to see the HBase tables that exist within the schema.

How do you describe an external table in Hive?

An external table is a table for which Hive does not manage storage. If you delete an external table, only the definition in Hive is deleted. The data remains. An internal table is a table that Hive manages.

How would you describe the view in Hive?

There is nothing like SHOW VIEWS in Hive. DESCRIBE and DESCRIBE EXTENDED statements can be used for views like for tables, however, for DESCRIBE EXTENDED, the detailed table information has a variable named typeable which has value = ‘virtual view’ for views. EXTERNAL and LOCATION clause also works for views.

What is Derby programming?

Derby is a full-featured, open source relational database management system (RDBMS) that is based on Java technology and SQL. Derby is written and implemented completely in the Java programming language. Derby ensures data integrity and provides sophisticated transaction support.

What is Derby Hadoop?

Apache Derby, an Apache DB subproject, is an open source relational database implemented entirely in Java and available under the Apache License, Version 2.0. Some key features include: Derby has a small footprint — about 3.5 megabytes for the base engine and embedded JDBC driver.

How do I show tables in Beeline?

Show activity on this post. By default, beeline / hive shell points to ‘default’ database. the tables listed above are the tables of the ‘default’ database / schema. Switch to the different database/schema using use database_name in this case: USE datalab_network , you will be able to see the tables.

How do you know if a Hive table is internal or external?

For external tables Hive assumes that it does not manage the data. Managed or external tables can be identified using the DESCRIBE FORMATTED table_name command, which will display either MANAGED_TABLE or EXTERNAL_TABLE depending on table type.

How can you identify whether a table is internal or external?

The Internal table is also known as the managed table. We can identify the internal or External tables using the DESCRIBE FORMATTED table_name statement in the Hive, which will display either MANAGED_TABLE or EXTERNAL_TABLE depending on the table type.