Sqoop 面试题与答案

问题 16. What is the purpose of the --direct-import option in Sqoop?

The --direct-import option is used to import data directly into the database without using HDFS as an intermediate storage.

问题 17. Explain the purpose of the --query option in Sqoop.

The --query option allows you to specify a SQL SELECT statement to retrieve data during Sqoop import.

Example:

sqoop import --connect jdbc:mysql://localhost:3306/db --query SELECT * FROM mytable WHERE $CONDITIONS --split-by id

问题 18. What is the purpose of the --null-string and --null-non-string options in Sqoop?

These options are used to specify the representation of NULL values in the imported data for string and non-string columns, respectively.

Example:

sqoop import --connect jdbc:mysql://localhost:3306/db --table mytable --null-string --null-non-string -1

问题 19. Explain the purpose of the --boundary-query option in Sqoop.

The --boundary-query option allows you to specify a SQL query that is used to determine the range of values for the splitting column.

Example:

sqoop import --connect jdbc:mysql://localhost:3306/db --table mytable --boundary-query SELECT MIN(id), MAX(id) FROM mytable

问题 20. What is the purpose of the --validate option in Sqoop?

The --validate option is used to perform data validation during import by comparing the source and target data counts.

Example:

sqoop import --connect jdbc:mysql://localhost:3306/db --table mytable --validate