How are views and temporary tables defined and used in Hive?

In Hive, a view is a virtual table that is based on the result set of a query, and can be queried like a table. To create a view, you need to use the CREATE VIEW statement and specify the view’s name, column names, and query statement. For example:

CREATE VIEW my_view AS
SELECT column1, column2
FROM my_table
WHERE condition;

After creating a view, you can use it just like querying a table.

SELECT * FROM my_view;

Temporary tables are tables that exist during a Hive session and are automatically deleted when the session ends. To create a temporary table, you need to use the CREATE TEMPORARY TABLE statement and specify the table’s name and column names. For example:

CREATE TEMPORARY TABLE temp_table (
column1 INT,
column2 STRING
);

After creating a temporary table, you can use it just like a regular table for querying.

SELECT * FROM temp_table;

It is important to note that the roles and usage of views and temporary tables in Hive are different. Views are typically used to simplify complex queries and repeated queries, while temporary tables are used for temporarily storing and processing data.