Cognizant Cognos 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.

DBA stands for Database Administrator. The architecture of DBA involves managing and maintaining databases to ensure data integrity and security.

• DBA is responsible for installing, configuring, and upgrading database software.

• They monitor database performance and troubleshoot issues.

• DBA designs and implements backup and recovery strategies to prevent data loss.

• They also manage user access and security permissions within...read more

Maintaining the database involves regular monitoring, performance tuning, applying patches, and ensuring backups are taken regularly.

• Regularly monitor database performance and usage

• Perform routine maintenance tasks such as applying patches and updates

• Take regular backups to ensure data integrity and disaster recovery

• Implement security measures to protect the database from unauthorized access

• Optimize database performanc

Join is used to combine rows from two or more tables based on a related column, while lookup is used to retrieve data from a reference table based on a matching key.

• Join combines rows from multiple tables based on a related column

• Lookup retrieves data from a reference table based on a matching key

• Join can result in duplicate rows if there are multiple matches, while lookup returns only the first matching row

• Join is use...read more

Fact table contains quantitative data and measures, while dimension table contains descriptive attributes.

• Fact table contains numerical data that can be aggregated (e.g. sales revenue, quantity sold)

• Dimension table contains descriptive attributes for analysis (e.g. product name, customer details)

• Fact table is typically normalized, while dimension table is denormalized for faster queries

• Fact table is usually larger in s

Use sed command to display the line before a specific pattern

• Use 'sed -n '/pattern/{g;1!p;};h' file.txt' to display the line before the pattern

• Replace 'pattern' with the specific pattern you are looking for

• This command will display the line before the pattern in the file

I joined inm because of the company's reputation for innovation and growth in the tech industry.

• Attracted to company's reputation for innovation

• Excited about opportunities for growth in tech industry

• Impressed by company culture and values

SQL architecture refers to the structure and components of a SQL database system.

• SQL architecture includes components like storage engine, query processor, and buffer manager.

• The storage engine manages data storage and retrieval, while the query processor processes SQL queries.

• The buffer manager handles caching and memory management to optimize performance.

• Examples of SQL architectures include MySQL, Oracle, and SQL Se

Data Stage is an ETL tool by IBM, while Informatica is a popular ETL tool by Informatica Corporation.

• Data Stage is developed by IBM, while Informatica is developed by Informatica Corporation.

• Data Stage is known for its parallel processing capabilities, while Informatica is known for its ease of use and flexibility.

• Data Stage has a graphical interface for designing jobs, while Informatica uses a more traditional workflo...read more