Yoshops Interview Questions and Answers

Joins are used to combine rows from two or more tables based on a related column between them.

• Types of joins include inner join, outer join (left, right, full), cross join, and self join.

• Inner join returns rows when there is at least one match in both tables.

• Outer join returns all rows from one table and matching rows from the other table.

• Cross join returns the Cartesian product of the two tables.

• Self join is used to j...read more

Data collection is the process of gathering and organizing information for analysis and decision-making.

• Data collection involves systematically collecting data from various sources.

• It can be done through surveys, interviews, observations, or by extracting data from databases.

• The collected data is then organized and stored for analysis and interpretation.

• Examples of data collection include conducting customer satisfacti...read more

Feature engineering is the process of selecting, transforming, and creating new features from raw data to improve model performance.

• Feature selection involves choosing the most relevant features for the model

• Feature transformation includes scaling, normalization, and encoding categorical variables

• Feature creation involves generating new features based on existing ones, such as polynomial features or interaction terms