Brave AI Lab Data Engineer Interview Questions and Answers

Supervised learning uses labeled data to train the model, while unsupervised learning uses unlabeled data.

• Supervised learning requires a target variable to be predicted, while unsupervised learning does not.

• In supervised learning, the model learns from labeled training data, whereas in unsupervised learning, the model finds patterns in unlabeled data.

• Examples of supervised learning include regression and classification...read more

Object Oriented Programming in Python focuses on creating classes and objects to organize code and data.

• Python supports classes, objects, inheritance, polymorphism, and encapsulation.

• Classes are blueprints for creating objects, which are instances of classes.

• Inheritance allows a class to inherit attributes and methods from another class.

• Polymorphism enables objects to be treated as instances of their parent class.

• Encap...read more

To find delta between two tables in SQL, use the EXCEPT or MINUS operator.

• Use the EXCEPT operator in SQL to return rows from the first table that do not exist in the second table.

• Use the MINUS operator in SQL to return distinct rows from the first table that do not exist in the second table.

Exception handling in Python allows for graceful handling of errors and preventing program crashes.

• Use try-except blocks to catch and handle exceptions.

• Multiple except blocks can be used to handle different types of exceptions.

• Finally block can be used to execute code regardless of whether an exception was raised or not.

• Custom exceptions can be defined by creating a new class that inherits from the built-in Exception c

Decorators in Python are functions that modify the behavior of other functions.

• Decorators are defined using the @decorator_name syntax before the function definition.

• They can be used for logging, timing, authentication, etc.

• Example: @staticmethod decorator in Python makes a method static.

Examples of IaaS, PaaS, and SaaS include AWS (IaaS), Google App Engine (PaaS), and Salesforce (SaaS).

• IaaS - Infrastructure as a Service: AWS, Microsoft Azure, Google Cloud Platform

• PaaS - Platform as a Service: Google App Engine, Heroku, Microsoft Azure App Service

• SaaS - Software as a Service: Salesforce, Google Workspace, Microsoft Office 365

ADF stands for Azure Data Factory, a cloud-based data integration service. ADB stands for Azure Databricks, an Apache Spark-based analytics platform.

• ADF is used for data integration and orchestration, while ADB is used for big data analytics and machine learning.

• ADF provides a visual interface for building data pipelines, while ADB offers collaborative notebooks for data exploration and analysis.

• ADF supports various da...read more

Spark is a distributed computing system that provides an interface for programming clusters with implicit data parallelism.

• Spark is built on the concept of Resilient Distributed Datasets (RDDs), which are fault-tolerant collections of objects.

• It supports various programming languages such as Scala, Java, Python, and R.

• Spark provides high-level APIs for distributed data processing, including transformations and actions.

• ...read more

Lazy evaluation is a strategy used by Spark to delay the execution of transformations until an action is called.

• Lazy evaluation improves performance by optimizing the execution plan

• Transformations in Spark are not executed immediately, but rather recorded as a lineage graph

• Actions trigger the execution of the transformations and produce a result

• Lazy evaluation allows Spark to optimize the execution plan by combining an...read more

Left join returns all records from the left table and the matching records from the right table.

• Inner join returns only the matching records from both tables.

• Left join includes all records from the left table, even if there are no matches in the right table.

• Inner join excludes the non-matching records from both tables.

• Left join is used to retrieve all records from one table and the matching records from another table.

• I...read more