Database migration testing in Testing Fundamentals - Practice Problems & Coding Challenges

Challenge - 5 Problems

🧠 Conceptual

intermediate

Purpose of Database Migration Testing

Why is database migration testing important when moving data from one system to another?

A To check if the user interface of the application looks good after migration.

B To ensure the network speed is faster after migration.

C To confirm that the database server hardware is upgraded.

D To verify that data is accurately transferred and no data loss or corruption occurs during migration.

💡 Hint

Think about what could go wrong with the data itself during migration.

Database migration testing focuses on verifying data integrity and correctness after moving data. It ensures no data is lost or corrupted.

❓ Predict Output

intermediate

Result of Data Count Check After Migration

Given the following SQL queries run before and after migration, what is the expected output if migration is successful?

-- Before migration
SELECT COUNT(*) FROM customers;
-- After migration
SELECT COUNT(*) FROM customers_new;

Testing Fundamentals

Before migration count: 1500
After migration count: 1500

A Both counts are equal, showing 1500 rows each.

B Before migration count is 1500, after migration count is 0.

C Before migration count is 0, after migration count is 1500.

D Both counts are different, before 1500 and after 1400.

💡 Hint

What does it mean if the row counts before and after migration match?

If the row counts are equal, it indicates that all data rows were migrated successfully without loss.

❓ assertion

advanced

Valid Assertion for Data Integrity Check

Which assertion correctly verifies that the 'email' field in the migrated 'users' table contains no NULL values?

Testing Fundamentals

assert migrated_data['email'].isnull().sum() == 0

A assert migrated_data['email'].count() == 0

B assert migrated_data['email'].isnull().sum() == 0

C assert migrated_data['email'].isnull().all()

D assert migrated_data['email'].sum() == 0

💡 Hint

Think about how to check that no NULL values exist in a column.

Checking that the sum of NULL values is zero confirms no NULLs are present in the 'email' column.

🔧 Debug

advanced

Identify the Error in Migration Test Script

What error will this Python snippet raise during migration testing?

def test_row_count(original, migrated):
    assert original.count == migrated.count

original = 1000
migrated = 1000

test_row_count(original, migrated)

A AttributeError because 'int' object has no attribute 'count'.

B AssertionError because counts are not equal.

C TypeError because count is not callable.

D No error, test passes successfully.

💡 Hint

Check the data types and attributes used in the assertion.

The variables are integers and do not have a 'count' attribute, causing AttributeError.

❓ framework

expert

Best Practice for Automating Database Migration Tests

Which approach is best for automating database migration testing to ensure data integrity and performance?

A Manually check data in the database using SQL queries after migration is complete.

B Only test the application UI after migration to see if it works without errors.

C Create automated scripts that compare row counts, data samples, and run performance benchmarks before and after migration.

D Run migration once and trust the migration tool without further testing.

💡 Hint

Think about thorough and repeatable testing methods.

Automated scripts that verify data and performance ensure consistent and reliable migration testing.