Embarking on a journey toward a career in data analytics is both thrilling and challenging, especially when aiming for prestigious companies like LatentView Analytics. Aspiring candidates often find themselves navigating through a maze of technical concepts and interview preparations to secure a coveted position in the data analytics realm. In this blog, we’ll unravel some of the key interview questions and provide insightful answers tailored specifically for LatentView Analytics. By delving into fundamental concepts and practical approaches, candidates can gain the confidence and knowledge needed to excel in their data analytics interviews and pave the way for a rewarding career at LatentView Analytics. Let’s dive in!
Table of Contents
Basic C and database questions
Question: What is the difference between malloc() and calloc()?
Answer: malloc() allocates a memory block of specified size but doesn’t initialize the memory, whereas calloc() allocates memory and initializes all bits to zero.
Question: What is a pointer?
Answer: A pointer is a variable that stores the memory address of another variable.
Question: What is the difference between ++i and i++?
Answer: ++i is pre-increment where the value of i is incremented before it is used. i++ is post-increment where the value is first used and then incremented.
Question: Explain the difference between array and pointer.
Answer: An array is a collection of elements of the same data type stored in contiguous memory locations. A pointer is a variable that stores the memory address of another variable.
Question: What is the purpose of void pointer?
Answer: void pointer is a generic pointer type that can hold the address of any data type. It is often used for memory allocation and function pointers.
Question: What is normalization and why is it important?
Answer: Normalization is the process of organizing data in a database to reduce redundancy and dependency. It ensures data integrity and prevents anomalies like insertion, update, and deletion anomalies.
Question: What are the ACID properties in a database?
Answer: ACID stands for Atomicity, Consistency, Isolation, and Durability. These properties ensure that database transactions are processed reliably.
Question: What is a primary key and foreign key?
Answer: A primary key is a unique identifier for a record in a database table. A foreign key is a field in a database table that is a primary key in another table. It establishes a link between two tables.
Question: What is a stored procedure?
Answer: A stored procedure is a precompiled collection of SQL statements that performs a specific task. It is stored in the database and can be executed by calling its name.
Questions based on SQL joins
Question: What are SQL joins and why are they important in database querying?
Answer: SQL joins are used to combine rows from two or more tables based on a related column between them. They are essential for retrieving data from multiple tables simultaneously, enabling the database to provide comprehensive information.
Question: Differentiate between INNER JOIN, LEFT JOIN, RIGHT JOIN, and FULL JOIN.
Answer:
- INNER JOIN: Returns only the rows where there is a match in both tables.
- LEFT JOIN (or LEFT OUTER JOIN): Returns all rows from the left table and matching rows from the right table. If there is no match, NULL values are returned for the columns from the right table.
- RIGHT JOIN (or RIGHT OUTER JOIN): Returns all rows from the right table and matching rows from the left table. If there is no match, NULL values are returned for the columns from the left table.
- FULL JOIN (or FULL OUTER JOIN): Returns all rows when there is a match in either table. If there is no match, NULL values are returned for the columns from the table without a match.
Question: When should you use a NATURAL JOIN?
Answer: NATURAL JOIN automatically joins the tables based on columns with the same name. It’s convenient when the column names are identical and there’s no ambiguity. However, it’s often considered risky in practice because it may not always produce the desired result if schema changes occur.
Question: What is the difference between JOIN and UNION?
Answer:
JOIN: Combines columns from two or more tables based on a related column between them.
UNION: Concatenates the result sets of two or more SELECT queries. It combines rows from different tables, but the tables need not have any common columns or relationships.
Question: Can you perform a JOIN operation without using the JOIN keyword?
Answer: Yes, JOIN operations can be performed using subqueries or WHERE clause conditions to establish relationships between tables. However, using the JOIN keyword is the standard and preferred method for clarity and readability.
Questions based on Azure Fundamentals
Question: What is Azure and what are its key components?
Answer: Azure is a cloud computing platform and service provided by Microsoft. Its key components include:
- Compute (Virtual Machines, App Service)
- Networking (Virtual Network, Load Balancer)
- Storage (Blob Storage, File Storage)
- Databases (SQL Database, Cosmos DB)
- Identity (Azure Active Directory)
- Management Tools (Azure Portal, Azure CLI)
Question: Explain the difference between Azure Virtual Machines and Azure App Service.
Answer:
- Azure Virtual Machines: Provides on-demand, scalable computing resources where users have full control over the virtual machine configuration and software installations.
- Azure App Service: A Platform-as-a-Service (PaaS) offering that enables developers to build, deploy, and scale web applications and APIs without managing the underlying infrastructure.
Question: What is Azure Active Directory (Azure AD) and what is its role in Azure?
Answer: Azure Active Directory is Microsoft’s cloud-based identity and access management service. It provides authentication and authorization services, allowing users to access Azure resources and other Microsoft online services. Azure AD also enables single sign-on (SSO) and integrates with on-premises Active Directory environments.
Machine Learning questions
Question: What is the difference between supervised and unsupervised learning?
Answer:
Supervised Learning: In supervised learning, the algorithm learns from labeled data, where each example is associated with a target label. The goal is to learn a mapping from inputs to outputs.
Unsupervised Learning: In unsupervised learning, the algorithm learns from unlabeled data and seeks to find hidden patterns or structures in the data.
Question: What are some common techniques for handling missing data?
Answer:
- Imputation: Replace missing values with a substitute value, such as the mean, median, or mode of the feature.
- Deletion: Remove rows or columns with missing values from the dataset.
- Prediction: Use machine learning algorithms to predict missing values based on other features in the dataset.
Question: Explain the difference between classification and regression.
Answer:
- Classification: Classification is a supervised learning task where the goal is to assign a label or category to input data. The output is discrete and categorical.
- Regression: Regression is also a supervised learning task where the goal is to predict a continuous value based on input data. The output is a real number.
Question: What is overfitting and how can it be prevented?
Answer: Overfitting occurs when a model learns to capture noise in the training data rather than the underlying patterns, leading to poor generalization performance on unseen data.
Techniques to prevent overfitting include cross-validation, regularization (e.g., L1 or L2 regularization), early stopping, and using simpler models.
Statistics Questions
Question: What is hypothesis testing?
Answer: Hypothesis testing is a statistical method used to make inferences about population parameters based on sample data.
It involves formulating null and alternative hypotheses, selecting a significance level, calculating a test statistic, and making a decision to reject or fail to reject the null hypothesis.
Question: Explain the difference between Type I and Type II errors.
Answer:
- Type I Error: Type I error occurs when the null hypothesis is incorrectly rejected when it is actually true. It is also known as a false positive.
- Type II Error: Type II error occurs when the null hypothesis is incorrectly not rejected when it is actually false. It is also known as a false negative.
Question: What is the Central Limit Theorem?
Answer: The Central Limit Theorem states that the sampling distribution of the sample mean approaches a normal distribution as the sample size increases, regardless of the shape of the population distribution.
This theorem is fundamental in statistics as it allows us to make inferences about population parameters using sample statistics.
Question: What is p-value in hypothesis testing?
Answer: The p-value is the probability of obtaining the observed results (or more extreme results) under the assumption that the null hypothesis is true.
A smaller p-value indicates stronger evidence against the null hypothesis, leading to its rejection in favor of the alternative hypothesis.
Question: What is an Excel sheet?
Answer: Excel Sheet:
- Spreadsheet file created using software like Microsoft Excel.
- Consists of a grid of cells arranged in rows and columns.
- Used for data entry, analysis, reporting, and visualization.
- Provides features for organizing and manipulating data.
- Suitable for managing small to medium-sized datasets.
Question: What is DBMS?
Answer: DBMS (Database Management System):
Software system for creating, managing, and interacting with databases.
Enables structured storage, retrieval, and manipulation of data.
Offers features like data integrity, security, and concurrency control.
Examples include MySQL, PostgreSQL, and Oracle Database.
Designed for managing large-scale databases shared among multiple users.
Other questions
- Write a program to check if a string is palindrome or not.
- How will you find duplicates in a given array?
- And they asked about Python and SQL
- Some basic questions on MySql.
- Write a program to reverse a string.
- Sorting questions in Python.
- Basic oops concept.
- Some questions from statistics.
General Questions
What are your salary expectations?
Questions on projects.
Why did you choose data analysis?
Conclusion:
Mastering the fundamental concepts and practical applications of data analytics is essential for success in interviews at esteemed companies like Latent View Analytics. By familiarizing themselves with key topics such as descriptive, predictive, and prescriptive analytics, candidates can demonstrate their expertise and readiness to tackle real-world business challenges. Additionally, staying updated with the latest trends and advancements in the field through continuous learning and networking is crucial for staying competitive. With a solid understanding of these concepts and a passion for data-driven decision-making, candidates can position themselves as valuable assets to companies like Latent View Analytics. Embracing these strategies will not only enhance candidates’ chances of success in interviews but also contribute to their overall growth and development in the dynamic field of data analytics.
