10+ Excelencia ITech Consulting Interview Questions and Answers

Window functions like lag and lead are used to analyze data over a specific range or window.

• Lag function can be used to calculate the difference between current and previous values in a time series data.

• Lead function can be used to calculate the difference between current and future values in a time series data.

• Window functions can be used to calculate moving averages, cumulative sums, and other statistical measures.

• For example, in finance, lag function can be used to calcula...read more

Methods and best practices for cleaning up data include removing duplicates, handling missing values, standardizing formats, and validating data accuracy.

• Remove duplicates by identifying and deleting identical records.

• Handle missing values by imputing with mean, median, or mode.

• Standardize formats by converting data into a consistent structure.

• Validate data accuracy by cross-referencing with external sources or using data profiling tools.

Best practices for optimizing SQL code

• Use indexes on columns frequently used in WHERE clauses

• Avoid using SELECT * and only retrieve necessary columns

• Optimize joins by using INNER JOIN instead of OUTER JOIN when possible

• Avoid using subqueries and instead use JOINs or CTEs

• Regularly analyze query performance using EXPLAIN or query execution plans

Indian economy is a developing economy with a lot of potential for growth.

• India is the world's sixth-largest economy by nominal GDP and third-largest by purchasing power parity.

• The economy has been growing at an average rate of 7% per year for the past decade.

• India has a large and growing middle class, which is driving consumption and demand for goods and services.

• The government has implemented several reforms to improve the business environment and attract foreign investment...read more

C and C++ are programming languages used for system programming and application development.

• C is a procedural programming language developed by Dennis Ritchie in 1972.

• C++ is an object-oriented programming language developed by Bjarne Stroustrup in 1983.

• C is used for system programming, embedded systems, and operating systems.

• C++ is used for application development, game development, and system programming.

• C++ is an extension of C with additional features like classes, inherit...read more

Visualization tools help to represent data in a graphical format for better understanding.

• Tableau - used for creating interactive dashboards and reports

• Power BI - used for data visualization and business intelligence

• Matplotlib - used for creating static, animated, and interactive visualizations in Python

• D3.js - used for creating dynamic and interactive visualizations on the web

• QlikView - used for data discovery and visualization

• Excel - used for creating basic charts and graph...read more

To increase India's economy, focus on infrastructure development, education, and promoting entrepreneurship.

• Invest in infrastructure development to improve connectivity and transportation

• Promote education and skill development to create a more skilled workforce

• Encourage entrepreneurship and innovation to create more job opportunities

• Increase foreign investment and trade to boost the economy

• Reduce corruption and bureaucratic red tape to improve ease of doing business

Bi, Tableau, and Snowflake are different tools used for different purposes in data analysis.

• Bi (Business Intelligence) is a software that helps in analyzing data and creating reports.

• Tableau is a data visualization tool that helps in creating interactive dashboards and reports.

• Snowflake is a cloud-based data warehousing platform that allows for easy and efficient data storage and retrieval.

• Bi and Tableau can be used together to create comprehensive reports and visualizations....read more

To call an API, you need to make a request to a specific URL with the appropriate method and parameters.

• Use a tool like Postman or cURL to make API calls

• Include the necessary headers and authentication tokens in your request

• Choose the appropriate HTTP method (GET, POST, PUT, DELETE) based on the API documentation

• Provide any required parameters or data in the request body or query string

• Handle the response from the API, which may be in JSON, XML, or other formats

Triggers in SQL are special stored procedures that are automatically executed or fired when certain events occur in a database.

• Triggers can be used to enforce business rules, audit changes, or maintain referential integrity.

• They can be defined to execute before or after an INSERT, UPDATE, or DELETE operation on a table.

• Examples: BEFORE INSERT trigger to validate data, AFTER UPDATE trigger to log changes.