Cassandra Practice Test

What does the "BEGIN BATCH" statement indicate in a batch write operation?

1. The start of a multi-statement transaction

2. A new partition creation

3. A command to delete existing data

4. Initialization of a read operation

The correct answer is: The start of a multi-statement transaction

The "BEGIN BATCH" statement indicates the beginning of a batch write operation, which allows multiple CQL (Cassandra Query Language) statements to be grouped together and executed as a single operation. This is particularly useful for ensuring that related updates are applied together, which can help maintain the consistency of data across multiple rows or tables in Cassandra. When using "BEGIN BATCH," any statements that follow it until "APPLY BATCH" are part of that batch operation. This means that the actions within the batch can be treated as a single atomic operation, with Cassandra ensuring that either all changes are applied or none at all in case of an error during execution. This mechanism is essential for scenarios where multiple related updates need to succeed or fail together, thus providing a level of transactional support. In this context, the other options do not accurately represent what "BEGIN BATCH" signifies. While creating a new partition or deleting existing data are valid actions within CQL, they are not specifically indicated by the "BEGIN BATCH" command. Similarly, initializing a read operation is distinct from the purpose of a batch write operation since "BEGIN BATCH" solely pertains to writing data, not reading it.