Column Software Solutions Interview Questions and Answers

SQL operations are actions performed on a database using SQL commands to retrieve, update, insert, or delete data.

• SQL operations include SELECT (retrieve data), INSERT (add new data), UPDATE (modify existing data), DELETE (remove data)

• SQL operations can also include creating and modifying database tables, indexes, and views

• Examples: SELECT * FROM table_name, INSERT INTO table_name (column1, column2) VALUES (value1, val...read more

Ranking in SQL is a way to assign a rank to each row in a result set based on a specified criteria.

• Ranking functions include RANK(), DENSE_RANK(), and ROW_NUMBER().

• RANK() assigns a unique rank to each distinct row, with gaps in the ranking if there are ties.

• DENSE_RANK() assigns a unique rank to each distinct row, with no gaps in the ranking if there are ties.

• ROW_NUMBER() assigns a unique sequential integer to each row ...read more

Normalization is the process of organizing data in a database to reduce redundancy and improve data integrity.

• Normalization is used to eliminate data redundancy by breaking up tables into smaller, related tables.

• It helps in reducing data anomalies such as insertion, update, and deletion anomalies.

• Normalization is achieved through a series of normal forms (1NF, 2NF, 3NF, BCNF, etc.).

• Example: A database table that stores...read more

To reduce redundancy, implement data normalization, use modular design, automate repetitive tasks, and utilize version control systems.

• Implement data normalization to eliminate duplicate data entries.

• Use modular design to create reusable components and avoid repeating code.

• Automate repetitive tasks using scripts or tools to save time and reduce errors.

• Utilize version control systems like Git to track changes and avoid ...read more

Caching is the process of storing data in a temporary location to reduce load times and improve performance.

• Use caching libraries like Redis or Memcached

• Identify which data needs to be cached based on frequency of use

• Set expiration times for cached data to ensure freshness

• Implement caching strategies like lazy loading or write-through

• Monitor cache performance and adjust as needed

Data is temporarily stored in memory during program execution.

• Data is stored in memory to be accessed quickly by the CPU.

• Memory is volatile, meaning data is lost when the power is turned off.

• Examples include variables, arrays, and objects stored in RAM.

To delete an activity, you can typically use a delete button or option within the application.

• Locate the activity you want to delete within the application.

• Look for a delete button or option next to the activity.

• Confirm the deletion when prompted.

• The activity should now be removed from the application.