10+ Solutionstar Interview Questions and Answers

The task is to determine the total number of ways to make change for a specified value using given denominations of coins.

• Create a function that takes the number of denominations, the denominations array, and the value to make change for as input parameters.

• Use dynamic programming to iterate through all possible combinations of coins to make the change.

• Keep track of the number of ways to make change for each value from 0 to the target value.

• Return the total number of ways to ...read more

The problem involves outputting elements of a 2D matrix in diagonal order, alternating directions.

• Iterate through the matrix diagonally, starting from the top-left element.

• Alternate the direction of traversal from bottom-left to top-right and vice versa.

• Handle large matrices efficiently by taking advantage of matrix properties.

• Example: For a 3x3 matrix [1, 2, 3, 4, 5, 6, 7, 8, 9], the output should be 1 2 4 7 5 3 6 8 9.

Use SQL query to generate a report of customer churn based on case study data.

• Identify the criteria for customer churn in the case study data (e.g. last purchase date, account status)

• Select the relevant fields from the database tables (e.g. customer ID, churn date)

• Filter the data to include only customers who meet the churn criteria

• Group the data by relevant time periods (e.g. monthly, quarterly) to analyze churn trends

• Calculate the churn rate by dividing the number of churne...read more

To maintain knowledge transfer of project/jobs developed, ensure documentation, training, and continuous communication.

• Document all project/job details, processes, and procedures.

• Provide training sessions to transfer knowledge and skills.

• Encourage continuous communication and collaboration among team members.

• Establish a knowledge sharing platform or repository.

• Conduct regular knowledge transfer meetings or workshops.

• Assign mentors or experienced team members to guide and supp...read more

An index in SQL is a data structure that improves the speed of data retrieval operations on a database table.

• Indexes are used to quickly locate data without having to search every row in a table.

• They can be created on one or more columns in a table.

• Examples of indexes include primary keys, unique keys, and non-unique indexes.

Fact and dimensions are components of a data warehouse. Facts are numerical data while dimensions are descriptive data.

• Facts are quantitative data that can be measured, such as sales revenue or number of customers.

• Dimensions are descriptive data that provide context for the facts, such as time, location, or product.

• Facts and dimensions are stored in a data warehouse, which is a large repository of data used for analysis and reporting.

• Facts are stored in fact tables, while dim...read more

Informatica Transformations are used to manipulate data during ETL process.

• Aggregator: performs calculations on groups of data

• Filter: filters rows based on a condition

• Joiner: joins data from two sources based on a common key

• Lookup: retrieves data from a database table or flat file

• Rank: assigns a rank to each row based on a specified column

• Router: routes data to different targets based on a condition

• Sorter: sorts data based on one or more columns

• Source Qualifier: extracts data...read more

SCD stands for Slowly Changing Dimensions. It is a technique used in data warehousing to track changes in data over time.

• Type 1 SCD: Overwrite the old data with new data. Example: Customer address change.

• Type 2 SCD: Create a new record for the change. Example: Employee promotion.

• Type 3 SCD: Create a new attribute to store the change. Example: Product price change.

• Type 4 SCD: Create a separate table to store the change history. Example: Customer purchase history.

Design a database for a startup to increase revenue.

• Identify key business processes and data requirements

• Design a relational database schema to store the necessary data

• Optimize the database structure for efficient querying and data retrieval

• Implement data validation and integrity constraints

• Consider scalability and future growth

• Leverage data analytics and business intelligence tools for revenue optimization

Dynamic lookup is done at runtime while status lookup is done at design time.

• Dynamic lookup is used when the lookup values are not known at design time.

• Status lookup is used when the lookup values are known at design time.

• Dynamic lookup requires more processing power as it is done at runtime.

• Status lookup is faster as it is done at design time.

• Example of dynamic lookup: retrieving a list of available payment methods from a database.

• Example of status lookup: selecting a status...read more