Legacy Database Migration: Effective Data Migration Plan

Upgrading and modernizing basic workflows and software systems is an essential step for any business that scales and adapts to shifting market demands. It is extremely important to keep all the existing and previously accumulated data intact and well-compatible with upgraded systems. For this, savvy companies migrate data from legacy database systems to new, up-to-date performing storage environments. Let’s dive into more details and figure out how to do data migration the right way.

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What is the Definition of Database Migration?

As you probably know, legacy data is historical data that’s buried in old databases and contains vital information for the organization. Being stored for ages, the legacy data becomes disordered, siloed, and segmented by different formats. Managing and processing such data becomes overly cumbersome and useless over time, making companies consider moving legacy databases to modern environments.

Database migration is a transition from an older database (DB) environment to a newer, more advanced system (e.g. cloud) while saving data value. Most of the time, data migration from legacy systems to a modern database means:

• upgrade to the latest version of the existing database (homogeneous migration);
• transfer to a completely new database from another vendor (heterogeneous migration, for example, from MySQL to PostgreSQL).

How to move from .NET Framework to .NET Core in a few steps? Read the article. How to Convert .NET Framework to .NET Core: Migration Guide

But how do you find out if you use a legacy database? Here are common examples of legacy databases:

• MS-DOS-operated proprietary software/hardware combinations (the oldest type of legacy systems);
• computerized library systems;
• your MySQL, Microsoft SQL Server, PostgreSQL, Oracle, or another database — if it is running on an IT infrastructure that hasn’t received proper updates for some time. 

If you are experiencing issues handling any of the above or having trouble defining the most fitting migration approach in your case, contact ModLogix for professional consultation on any questions on legacy application modernization.

5 Benefits of Database Migration 

Now let’s define the main benefits of legacy database system migration.

Cost reduction

Legacy systems run on stale software that must be scrupulously maintained and upgraded with the help of extra integrations and whatnot. And the maintenance and optimization of such systems requires additional expertise and manpower while tinkering with out-of-date software is always an overly time-consuming process. All of which results in significant yet unnecessary expenses. On top of that, the legacy infrastructure has limited capacities, which hinders business expansion by restricting technical scaling opportunities.

Timely migration is what can help you avoid both extra costs and tech restrictions by achieving a system that’s more flexible, secure, and overall reliable in terms of the underlying infrastructure. A migrated and modernized system runs smoother, employs updated security mechanisms, and is easier to support. Streamlined software performance goes a long way, reflecting on the end quality of services.

Do you want to know how expensive is it to maintain legacy software? The Cost of Maintaining Legacy Systems: How Much You Overpay

Capability enhancement

Data accessibility

Comprehensive data integrity

Legacy database migration preserves data dependencies, allowing developers to conveniently redesign the system. This means that the data remains integral, and the default access settings are saved. The overall data integrity is paramount as the quality of data translates into the quality of decisions made based on that data. And such decisions are usually crucial for setting the business direction and achieving better market results based on the detailed analysis of demand and trends.

Organizing data in legacy systems often turns to a real challenge. Learn How to Effectively Conduct a Legacy System Integration

Versatile scaling

Without causing any essential proprietary difficulties, a cloud system can easily be scaled to accommodate more users, manage more tasks, and cope with higher performance intensity. All of this is possible because cloud capacity can be scaled to almost any level on the provider’s end. To scale quickly, you don’t need to worry about all the server/storage/network equipment management, licensing, and other administrative tasks. This comes in as a real time- and nerve-saver.

What Are the Main Data Migration Requirements?

Finally, we got to the stage of discussing the data migration requirements that must be met before proceeding with the migration procedure.

Data audit

A legacy database is a poorly structured, heterogeneous, and often unused set of data. In order to eliminate errors in the dependencies between these data sets after the upcoming migration, you have to audit them. If you ignore this step, unexpected problems may arise. In addition, you should understand that you need to move not only data but also the business logic implemented on the database side. 

You should be careful here: business logic in the old system can be written in various programming languages; therefore, simply copying it to a new system means transferring all existing errors along (and possibly adding new ones).

Solving data issues

Maintaining data security

Databases are one of the most vulnerable targets for cyber attacks. However, there are various tools on the market today to make data transfer secure, such as intrusion detection systems, security analytics, and firewalls.

In addition, your team needs to understand what data they will have to deal with and how it will be used within the system. Ignoring this step can lead to a fatal data mapping error.

Track data quality and generate reports

The state of the existing database and reporting on the data stored in it must be monitored. At the same time, the processes and reporting tools should be convenient and, where it is possible, automated.

7 Steps of Data Migration Process

So, how to migrate from legacy database? According to our experience, this process involves seven consecutive stages. Below we will look at each of them.

Audit the legacy database

Before the migration procedure, you must carefully analyze the data with which you are dealing: what is the structure of this data? What is its type? Does it have dependencies? What fields are missing? Perhaps some of them are no longer used, and there is no need to migrate these data from legacy database to a new database. If some parameters are missing, they will have to be replenished as far as possible so that the system will work correctly in the future.

Plan your migration scenario

You have two data migration techniques: Big Bang (the first of two data migration approaches that implies stopping the business processes in which the old database is involved; runs within a strictly predetermined time frame) or gradual migration (this data migration approach does not require suspension of work processes). At this stage, after choosing which one of the types of data migration is the most suitable to your needs and tech requirements, you also need to select the appropriate migration tools and complete a list of specifications (including security).

Make the data backup

Do not forget to back up your data so that in case of incorrect migration you can return to the previous steps without loss. Data backup is a timely effort to copy all the migrated data and store it someplace to easily recover any lost or damaged assets in case certain mid-migration issues take place.

Design the target system

With the backup in place, the data can now be moved to a new better environment. The essential step of the way, however, is to have that environment running and ready to receive all the migrated data. The migration solution can be custom-made or readymade – depending on your needs and goals, you may want to build a tailored solution for more versatility or use a readily available platform for fast and cost-efficient migration. The final solution depends on your goals and resources.

Test your new database

Test the new database with real data at all planned stages (not just at the end of the migration procedure). For instance, when it comes to migrating large amounts of data, testing can be done synchronously with all the steps of data migration. This is how you can understand how correctly the procedure was carried out and see whether everything runs properly (business logic, connections, etc.).

How to test a legacy codebase without breaking anything? Learn here. Testing Legacy Codebase: What is, Common Problems and Best Practices

Run the updated solution

After a successful final testing procedure, you can launch the updated system for public use. This is where you also may need profiled assistance to properly deploy software in the required environment.

Support and maintain the system

During the first weeks of the updated system, you can continue to test it using automated tools to eliminate the possibility of errors. Post-release support and maintenance help further adapt the system to new working conditions and perfect its performance.

What Determines the Cost of the Legacy Database Migration Procedure?

The pricing of the legacy database migration process depends on several factors:

• the amount of code running on the side of the legacy database;
• the amount of data stored in the legacy database;
• the time allotted for switching from one system to another;
• semantic differences in the programming languages ​​of the legacy and new database.

The cost of the procedure may increase if you still need to support and maintain the existing legacy database while preparing for the upcoming migration. The migration process is also often associated with architectural improvements to the legacy database, which also implies additional costs.

5 Common Pitfalls in Data Migration

As the practice shows, even if you have a well-thought-out, thorough plan, you may still come across certain pitfalls. This is why it is especially important to come armed with knowledge about the most common pitfalls.

Poor data quality 

The most global complexity in the migration procedure is bringing the data to the desired quality. That’s why it is essential to pay special attention to the analysis of data and its relationship with the business logic of the existing system. Otherwise, duplicated data or, for example, data presented in a binary code can provoke errors in the operation of the updated system.

Lack of expertise

Alternatively, you may face a lack of qualified personnel who can fully understand the logic of the new and old system. To complete the migration, the hired team must be competent in both the existing database management tools and the target ones. This significantly saves time and reduces the risk of errors. But even with the redundancy of the IT services market, there are few teams who are able to choose the data migration strategy correctly.

How to choose a qualified modernization vendor who'll guide you through the migration? Just ask these 9 Questions to Validate Your Legacy Modernization Vendor Before Starting the Cloud Migration Process

Low speed of SQL queries processing

Many organizations face the problem of insufficient SQL queries processing speed even after data migration from legacy systems. This flaw can be addressed with dedicated performance optimization tools such as Ever SQL Query Optimizer, My SQL, Maris DB, and Percona DB. 

You can also initially allocate excess memory resources to maximize the processing capacities of the system when needed. In exceptional situations, data defragmentation can be a way out.

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Cross-object dependencies 

Despite the plethora of legacy database transfer tools and strategies, cross-object dependencies can still be often discovered only after the launch of a new system and thus entail additional rework and time costs. Profiled specialists can employ a number of approaches and tools to cope with them. The main thing is to do it all timely.

The first testing procedure comes with unexpected outcomes, scenarios, and unexplained problems 

Even with the correctly chosen database migration strategy and the end-to-end data validation that precedes the legacy database migration procedure, testing a new database can produce unexpected results. This is why you will have to carefully revise the data again under different scenarios.

Consider ModLogix as Your Legacy Database Migration Partner

ModLogix is one of the few IT companies experienced in legacy modernization services. We use our data migration best practices: conduct a full audit of your data, bring it to a single ordered and structured form, and only after that — conduct the transfer procedure. Here is one of our major data migration examples in this area — seamless integration of cloud-based eligibility verification platform with EMR.

We decided to conduct a legacy system integration with the API to ensure end-to-end compatibility and the fastest data retrieval possible.

At the product owner’s request, we have organized compatibility with HL7, X12 EDI, XML, FHIR, thanks to the correct data standardization. Taking into account the colossal data amount, we have developed a unique data migration solution — web scraper — so that the data import and processing procedures are conducted in one click.

As a result, the speed of report generation increased 12.3 times, the client base grew by 43%, and the number of requests processed per day reached 15,000.

Learn from others, then implement best practices on your projects. 3 Legacy Software Modernization Case Studies and 12 Lessons We’ve Learned

Modernization of databases through legacy system migration to web applications is paramount. Depending on the particular case, updating a database may be a custom desire or an important requirement (as in the case of AngularJS ‌to‌ ‌Angular‌ ‌migration‌).

Final Thoughts

After the legacy data migration, the company reduces the costs of maintaining irrelevant systems and IT infrastructure as a whole, optimizing it by moving all data to one place, and creating an additional barrier against malicious attacks. This is especially true in the era of big data, when it is necessary to use innovative and efficient data storing methods. 

On the other hand, data migration from a legacy database to another is a complex and significant business process — the need to save data integrity requires specialists to be extremely correct and follow a well-thought-out strategy. If you are looking for a dedicated team that will perform database legacy migration the right way, please contact ModLogix. Leave your request, and we will respond shortly!