Top Interview Questions & Answers for Apache Sqoop

Using two file formats, Sqoop facilitates data import. The like:

i) Delimited Text File Format

This is the default file format used for importing data using Sqoop. In addition, this file type can be explicitly selected for the Sqoop import command with the –as-textfile argument. Similarly, supplying this parameter will generate a string-based representation of all the records in the output files, with delimited rows and columns.

ii) Sequence File Format

The Sequence file format may be described as a binary file format. Their records are kept in record-specific custom data types that are shown as Java classes. In addition, Sqoop builds these data types and presents them as Java classes automatically.

Sqoop enables users to Export and Import data depending on the WHERE clause.

Syntax:

-columns
 -where
-query

The fundamental Apache Sqoop controls and their functions are as follows:

• Export: This function allows the HDFS directory to be exported as a database table.
• List Tables: This function would assist the user in listing all tables in a certain database.
• Codegen: This method will allow you to develop code for interacting with various sorts of database records.
• Create: This function allows the user to import the table definition into the database hive.
• Eval: This function will always assist you in evaluating the SQL statement and displaying the results.
• Version: This function will assist you in displaying information connected to the database’s text.
• Import all tables: This function assists the user in importing all tables from a database to HDFS.
• List all the databases: This method would allow a user to generate a list of all databases on a specific server.

Sqoop requires a connector to link the various relational databases. Sqoop requires a JDBC driver of the database to interface with it. Nearly all database manufacturers offer a JDBC connector unique to their database.No, Sqoop requires both JDBC and a connector to connect to a database.

To utilize Sqoop in a Java program, the Sqoop jar must be included in the classpath. If we want to use Sqoop in a Java application, we’ll have to define every single parameter programmatically. The Sqoop.runTool() method must be called after this step.

Ans. Therefore, let’s explore all the distinctions based on their respective characteristics.

a. Data Flow

Sqoop is compatible with any relational database management system (RDBMS) that has a basic JDBC connection. In addition, Sqoop can import data from NoSQL databases such as MongoDB and Cassandra. Additionally, it supports data transmission to Apache Hive and HDFS.

Similarly, Apache Flume works with streaming data sources that are continually created in Hadoop systems. Like log files.

b. Type of Loading

Apache Sqoop – Sqoop load is not primarily driven by events.

Apache Flume – In this case, data loading is entirely event-driven.

c. When to use

Apache Sqoop — However, if the data is stored in Teradata, Oracle, MySQL, PostgreSQL, or any other JDBC-compatible database, it is a good fit.

Apache Flume – It is the greatest option for moving the majority of streaming data from sources such as JMS or spooling directories.

d. Link to HDFS

Apache Flume – Typically, Apache Flume data go to HDFS via channels.

Apache Flume – Data typically travel to HDFS using channels in Apache Flume.

e. Architecture

Apache Sqoop – Its architecture is built on connectors. However, this implies that the connectors are well-versed in interacting with numerous data sources. Similarly, data must be retrieved.

Apache Flume, on the other hand, has an agent-based architecture. Essentially, it implies that code developed in Flume is referred to as an agent, and it is responsible for obtaining data.