HP India Data Analyst Interview Questions and Answers

SQL rank order function explanation

• Rank order function in SQL assigns a rank to each row based on a specified column

• It can be used to determine the top or bottom N records in a dataset

• Example: SELECT column1, column2, RANK() OVER (ORDER BY column3 DESC) AS rank_order FROM table_name

Merging two tables involves combining data from both tables based on a common key.

• Identify a common key between the two tables

• Use SQL JOIN statements to merge the tables

• Choose the appropriate type of join (e.g. inner join, outer join)

• Consider the size of the tables and the performance implications of the merge

XGBoost is a popular machine learning algorithm known for its speed and performance in gradient boosting.

• XGBoost stands for eXtreme Gradient Boosting.

• It is an implementation of gradient boosted decision trees designed for speed and performance.

• XGBoost is widely used in machine learning competitions and has become a popular choice for data scientists.

• It can handle missing data and is optimized for parallel processing.

• XG...read more

Decision tree is a predictive modeling tool that uses a tree-like graph of decisions and their possible consequences.

• Decision tree is a supervised learning algorithm used for classification and regression tasks.

• It breaks down a dataset into smaller subsets based on different attributes.

• Each internal node represents a feature or attribute, each branch represents a decision rule, and each leaf node represents the outcome...read more