Question

What does the split-by parameter tell Sqoop?

A. The number of rows to commit per transaction.
B. The table name to export from the database.
C. The column to use as the primary key.
D. The number of rows to send to each mapper.

Answer 1

The split-by parameter in Sqoop specifies the column to use for splitting the work during an import operation, often acting as a proxy for the primary key.

Step-by-step explanation:

The split-by parameter in Sqoop is used to specify the column that Sqoop should use to split the work amongst the mappers during an import operation. When you perform data import, Sqoop tries to parallelize the transfer process to increase throughput; this is done by splitting the input dataset into multiple chunks, which are then processed in parallel. If you do not use the split-by parameter, Sqoop will automatically use the primary key column of the table for splitting. However, if the primary key is not suitable for splitting or if you are importing a view which doesn't have a primary key, you may choose another column that has a good distribution of data using the split-by parameter.

Therefore, the correct answer to the student's question is:
C. The column to use as the primary key.