Sqoop:

• Sqoop  is an open source tool that allows user to extract data from structured data store into  hadoop for further processing.
• After loading data into HDFS , it can be processed by map reduce or any other high level language like hive etc.
•  Data can be loaded from HDFS to relational databases for user.
•  By default, Sqoop will generate comma-delimited text files for imported data.
• Sqoop uses primary key of relational table for splitting. Each split will be process by individual mapper..
• Sqoop will run 4 mapper by default to load data into HDFS.
• User can change number of mapper by property  –m  <no. of mapper>