Data Migration

To best understand why Data Migration Testing (and Data Integration) is important, it is key to have a full understanding of Data Migration itself. This includes why it would be performed, how it would be performed, and the impact the testing has on the migration, as well as the Data Migration tool itself.

Data Migration is a process that includes moving data between formats, computer systems, and storage types.

The reasons to migrate include:

• Upgrading computer systems
• Changing computer systems
• Merging systems (Data Integration)

Improved technology often means business is thriving and is improving
alongside its competitors. That said, the act of migrating data can leave previous information vulnerable. If critical data is lost, the business could be left at a standstill.

Data Migration Testing

Migration Testing verifies the process of migrating the data from the legacy, or current system, to the new destination system. It does so with limited downtime and no loss of data or issues with data integrity. Furthermore, it does so while simultaneously making sure that all aspects — both functional and non-functional — of the application, are met post-migration. These outputs are all imperative to the success of any Data Migration. The data needs to be moved, maintain its function, and needs to be intact when it arrives at its destination.

As a first step, it makes sense to test the migration process or at least part of it without putting any actual data at risk. This allows you to both test and validate the migration plan.

During the migration testing, you should evaluate whether any modifications are required to the migration tools, the timeline, or the amount of data being migrated in each session. It isn’t just the data that may not go as planned. Many of these migration functions may also need to be tweaked before the move takes place.

Successful testing ultimately leads to being able to make use of automated migration, which allows you to free up physical bodies from having to do the work. It is essentially working out any potential risks before running the actual migration.

Checkout: Data Migration Checklist

Conducting the Testing

There are several steps taken to perform a successful test of the data
migration, whether carried out alone using the latest data migration software or through professional data migration services. The
process includes:

• Balancing: Ensure that the data records between the two systems
  are completely synced. To securely complete that syncing, it's crucial to ensure a perfect load balance between the legacy system and the destination system.

• Verification: To verify the correct migration as designed by the
  legacy’s mapping requirement, every business rule or logic for each of the data fields must be verified.

• Validate Data Integrity: Verify all source data as it relates to meeting expectations. Maintaining data integrity is a key component of migration testing.

• Test for functionality: Ensure that no functionality has changed between the two systems. Everything on the destination system should work exactly as it did on the legacy system. This includes time. It should not take longer to perform any function on the destination system as it did on the legacy system.

There are a few preparatory steps that are imperative before engaging in
data migration or its testing to maintain the data’s integrity should anything
go wrong including:

• Back-ups: If there is an issue with any migration, it is crucial to have back-ups for both the legacy system and the destination database.

• Create SQL queries: These should cover the full scope of the testing.

Why is it Important?

As discussed, the migration itself can take place for several different reasons. The most common of these reasons include getting rid of old technology, consolidating two or more systems, and optimizing performance. It is a crucial function that allows data to be maintained while being transferred to a newer, improved system. Migration Testing is employed before any automated migration takes place.

Given that it involves all the data owned and used by a business or
organization, testing the migration process is crucial to its success and to
maintaining the integrity of the data being moved. It is crucial to minimize,
or eliminate altogether, any potential issues through the testing phase. These issues might include:

• Disruption in the form of lost data or downtime.
• Loss of use of some features or reduced functionality.
• Other glitches may take place during the actual migration.

While avoiding the above issues is crucial to a successful migration,
there are other reasons as well including:

1. Ensuring compatibility between the legacy and destination system.
2. Double-checking existing functionalities in the destination system. Functions should perform precisely the same way they did in the legacy system.
3. Fixing any defects. Defects are prevalent during migration, many of which relate to the data. These defects must be found and fixed during migration testing.
4. Double-checking response times. Similar to functionality, the response time of the new system should be the same—or less—than in the legacy application.
5. Ensuring the connectivity between all hardware, servers, and software is maintained and does not fail during testing.

Automated Data Migration

Data can be migrated manually, but it can also be moved using an
automated function. By performing data migration testing, automated migration can be used more efficiently and confidently.

A common reference to performing a data migration task is the function
of ETL, which means Extract, Transform and Load. This ETL function sees
extracted data being fixed and then placed into the target data warehouse.

Importance of Data Migration Testing

There are some challenges that could arise during data migration
testing, which is precisely why the testing itself is so crucial. Some of these challenges include:

• Data corruption
• Unintended data modifications in the legacy system
• Unintended modifications in the data structures mapping

By uncovering these issues during the manual testing phase, they can be
fixed before an automated system starts the actual migration. Ultimately,
catching data corruption before it happens can be priceless.

Testing the mapping or path of data is another crucial component. Finding
any unintended modifications in that data mapping can also cure a major
headache during the automated phase.

Conclusion

Data is a critical component to the success of any business. That data
needs to be easily accessible and found in its rightful place, on the right
the system, and using the correct optimization.

Maintaining its integrity is of the highest importance. While moving
information and data from one system to another can be an absolute necessity, especially when it improves overall performance, but there are risks.

During every single migration, there stands the possibility of data
corruption or missing data. There are other issues that arise as well.
Functionality can be lost. Features may no longer be available. The time it
takes to perform a given function may be different than it was on the legacy system. All these issues can arise during migration and they can all be detrimental to a business’ short-term functionality.

To avoid these risks as much as possible, do not take shortcuts when it comes to a data migration strategy and protecting every aspect of data. Data migration and data cleansing are crucial business processes. The testing that is performed on data migration ensures that data is kept intact and readily available.