Data Migration Consultant Interview Questions and Answers

Migrating on premise application to cloud involves assessing current infrastructure, selecting appropriate cloud provider, planning migration strategy, testing and executing the migration.

• Assess current infrastructure and application dependencies

• Select appropriate cloud provider based on requirements (e.g. AWS, Azure, Google Cloud)

• Plan migration strategy including data migration, application migration, and testing

• Execute migration plan ensuring minimal downtime and data loss

• M...read more

Null data values in joins can be handled using COALESCE function or LEFT JOIN with IS NULL condition.

• Use COALESCE function to replace null values with a specified default value

• Use LEFT JOIN with IS NULL condition to include rows with null values in the result set

• Consider using CASE statements to handle null values based on specific conditions

I have used Linux extensively for data migration tasks.

• Performed data migration tasks using Linux command line tools

• Utilized shell scripting to automate data migration processes

• Worked with various file systems on Linux for data storage and transfer

• Configured and managed servers running on Linux for data migration purposes

Data migration involves transferring data from one system to another while ensuring data integrity and accuracy.

• Assess the source and target systems to determine the scope of migration

• Extract data from the source system and transform it to fit the target system

• Load the transformed data into the target system and validate it for accuracy

• Perform testing and reconciliation to ensure data integrity

• Implement post-migration activities such as data archiving and cleanup

SQL query order of execution determines the sequence in which different parts of a query are processed.

• SQL query is parsed and checked for syntax errors

• Query optimizer creates an execution plan

• Data is retrieved from tables based on the execution plan

• Filters and joins are applied to the retrieved data

• Aggregations and calculations are performed on the filtered data

Joins are used to combine rows from two or more tables based on a related column between them.

• Types of joins include INNER JOIN, LEFT JOIN, RIGHT JOIN, and FULL JOIN.

• INNER JOIN returns rows when there is at least one match in both tables.

• LEFT JOIN returns all rows from the left table and the matched rows from the right table.

• RIGHT JOIN returns all rows from the right table and the matched rows from the left table.

• FULL JOIN returns rows when there is a match in one of the tabl...read more