ACID (Atomicity, Consistency, Isolation, Durability) is a set of properties that ensure reliable and secure transaction processing in databases. The ACID properties provide a guarantee that transactions in a database will be processed correctly, even in the event of system failures or crashes.

In Hive, ACID transactions were introduced in Hive version 0.14 and later to provide support for transactional processing. Hive ACID transactions allow multiple users to make updates to the same data in a controlled manner, while ensuring that the data remains consistent and reliable.

Here is a simple example of how ACID transactions can be used in Hive:

-- Start a transaction
START TRANSACTION;

-- Insert data into a table
INSERT INTO sales (item_id, sale_date, sale_amount)
VALUES (1, '2021-01-01', 100.0);

-- Commit the transaction
COMMIT;

In this example, we start a transaction and insert data into the “sales” table. By using a transaction, we ensure that the data is inserted atomically, meaning that either all the data is inserted or none of it is inserted. If there is an error during the insertion process, the transaction will be rolled back, ensuring that the data remains consistent. Finally, we commit the transaction to make the data changes permanent.

Hive ACID transactions provide a way to perform reliable and secure updates to data stored in Hive, making it suitable for use in applications that require transactional processing.