Big Data Interview Questions and Answers- Sqoop

1) purpose of sqoop?ans : To import and export data from rdbms to hdfs and vice versa.

2) sqoop job?ans : Sqoop job creates and saves the import and export commands. It specifies parameters to identify and recall the saved job. This re-calling or re-executing is used in the incremental import, which can import the updated rows from RDBMS table to HDFS.

3) command to execute a sqoop job?ans : sqoop job --exec myjob

4) codegen in sqoop?ans : From the viewpoint of object-oriented application, every database table has one DAO class that contains ‘getter’ and ‘setter’ methods to initialize objects. This tool (-codegen) generates the DAO class automatically.It generates DAO class in Java, based on the Table Schema structure. The Java definition is instantiated as a part of the import process. The main usage of this tool is to check if Java lost the Java code. If so, it will create a new version of Java with the default delimiter between fields.

5) sqoop workflow in oozie?ans : ...foo:8021bar:8020mapred.compress.map.outputtrueimport --connect jdbc:hsqldb:file:db.hsqldb --table TT --target-dir hdfs://localhost:8020/user/tucu/foo -m 1...(or)...foo:8021bar:8020import--connectjdbc:hsqldb:file:db.hsqldb--tableTT--target-dirhdfs://localhost:8020/user/tucu/foo-m1...6)import subset of tableDate?ans : sqoop import \--connect jdbc:mysql://localhost/userdb \--username root \--table emp_add \--m 1 \--where “city =’sec-bad’” \--target-dir /wherequery7) import incremental import?ans : sqoop import \--connect jdbc:mysql://localhost/userdb \--username root \--table emp \--m 1 \--incremental append \--check-column id \-last value 1205