Cognizant Senior Test Engineer Interview Questions and Answers

Program to manipulate an array of strings

• Use string manipulation functions like substring, concat, etc.

• Iterate through the array using loops

• Consider sorting or searching algorithms if needed

Comparing tables without MINUS keyword

• Use JOIN clause to combine the tables and compare the columns

• Use UNION ALL to combine the tables and GROUP BY to compare the columns

• Use EXISTS clause to check if a record exists in both tables

• Use NOT EXISTS clause to check if a record exists in one table but not in the other

SCD stands for Slowly Changing Dimensions, which are used in data warehousing to track changes in data over time.

• SCD is used to maintain historical data in a data warehouse

• There are three types of SCD: Type 1, Type 2, and Type 3

• Type 1 SCD overwrites old data with new data

• Type 2 SCD creates a new record for each change and maintains a history of changes

• Type 3 SCD adds new columns to the existing record to track changes