Cognizant Teradata Developer Interview Questions and Answers

Analytical functions are used to perform calculations across a set of rows related to the current row.

• Analytical functions operate on a group of rows and return a single result for each row

• They can be used to calculate running totals, moving averages, rank, percentiles, etc.

• Examples include ROW_NUMBER(), RANK(), SUM() OVER(), AVG() OVER()

The Slowly Changing Dimension Type 2 (SCD2) transformation is used for handling historical data changes in a data warehouse.

• SCD2 transformation is used to track historical changes in dimension tables.

• It maintains multiple versions of a record by adding new rows with updated information and end-dating the previous record.

• Commonly used in scenarios where historical data needs to be preserved and queried.

• Example: When a c...read more

To find the count of different types of joins between two tables A and B.

• Left join: Includes all records from table A and matching records from table B.

• Right join: Includes all records from table B and matching records from table A.

• Inner join: Includes only the matching records from both tables.

• Full outer join: Includes all records when there is a match in either table A or table B.

I have used HUDI and Iceberg in my previous project for managing large-scale data lakes efficiently.

• Implemented HUDI for incremental data ingestion and managing large datasets in real-time

• Utilized Iceberg for efficient table management and data versioning

• Integrated HUDI and Iceberg with Apache Spark for processing and querying data