What is Database Migration?

Database Migration Explained

Database migration — in the context of enterprise applications — means moving your data from one platform to another. There are many reasons why you might want to migrate to another platform. For example, a company may decide to save money by migrating to a cloud-based database. Or, the company may find that certain database software has functions that are critical to its business needs. Or, the legacy system is simply obsolete. The database migration process may involve multiple stages and iterations-including evaluating the company's current database and future needs, migration models, and normalizing and moving data. In addition, testing, testing, and more testing.

Types of Database Migration

There are several different types of migrations used in database management to modify, transfer, or adjust database components. We will discuss here schema, data, and applications migrations and have a closer look at their specific purposes.

1. Schema Migration

This type of migration refers to the process of migrating the relational database schema or structure from one system to another. It involves modifying the schema, such as adding or removing tables, columns, indexes, or constraints, to accommodate changes in business requirements or to improve performance. This database migration is often necessary when transitioning to a new database management system (DBMS) or when upgrading to a new version of the same DBMS.

Definition and Purpose

This migration aims to ensure that the database schema remains consistent and functional during the migration process. It allows businesses to adapt their database structure to evolving needs, improve data organization, and optimize query performance.

Common Scenarios:

• Upgrading to a new version of a DBMS.

• Migrating from one DBMS to another (e.g., Oracle to MySQL).

• Modifying the schema to support new features or functionalities.

• Consolidating multiple databases into a single database.

2. Data Migration

Data migration involves transferring data from one database system to another, typically when transitioning from an old system to a new one. It includes moving data from the source database, transforming and reformatting it as required, and loading it into the target database. Data migration is crucial for maintaining business continuity, preserving data integrity, and enabling the use of new functionalities or technologies.

Definition and Purpose

Data migration aims to ensure a smooth and accurate transfer of data from the source to the target system. It involves extracting, cleaning, transforming, and validating data to ensure its quality and consistency in the new environment.

Common Scenarios:

• Upgrading to a new version or a different DBMS.

• Data migration to a cloud-based database service.

• Consolidating data from multiple sources into a single database.

• Transferring data from legacy systems to modern applications.

3. Application Migration

Application migration involves migrating the applications that interact with the database to a new system or environment. This includes migrating the application code, configurations, and dependencies to ensure proper functioning with the migrated database. Application migration is necessary when upgrading or changing the underlying database infrastructure, operating system, or application framework.

Definition and Purpose

Application migration ensures that the applications relying on the database remain compatible and functional in the new environment. It involves transferring the application logic, integrating it with the migrated database, and testing for any compatibility issues.

Common Scenarios:

• Upgrading the database system or application framework.

• Migrating applications to a cloud-based infrastructure.

• Moving applications from on-premises to a virtualized or containerized environment.

• Adapting applications to work with different database technologies.

The Benefits of Database Migration

Cost

One of the main reasons companies migrate their databases is to save money. Companies usually migrate from on-premises databases to cloud databases. This saves the infrastructure and the manpower and expertise required to support it.

Modern Software

Another common reason for migration is to migrate from an outdated or legacy system to a system designed to meet the needs of modern data. In the era of big data, new storage technologies are necessary. For example, a company may choose to migrate from an old SQL database to a data lake or other flexible system.

One Source of Truth

Another common reason for migrating data is to move all data to a place that can be accessed by all departments of the company. Sometimes, when the system needs to be combined, this will happen after the acquisition. Or, this happens when different systems are isolated throughout the company. For example, the IT department may use one database, and the marketing group uses another database, and these systems cannot "talk" to each other. When you have incompatible different databases, it is difficult to gain insights from your data.

Database Migration Challenges

Database migrations can be very complicated, but with proper planning, these common challenges can be alleviated:

Challenge #1: Find scattered databases

If your company has existed for a while, there may be many different databases in each department of your company. They may be in different departments and different regions. They may have been brought in through acquisitions. Part of the task of migrating the database is to locate the different databases in the company and plan how to normalize the data and transform the model.

Challenge #2: Data loss or corruption

When migrating a database, it is important for the database migration team to ensure that the data is moved safely without loss or damage. You need to plan how to test for possible data loss or corruption when moving data from one system to another.

Challenge #3: Security

When you move data from one platform to another, the security of the data is paramount. Unfortunately, there are many evil actors who want to get your stored personal data. As part of the migration process, you can choose to encrypt data or delete personally identifiable information (PII).

How Is the Database Migration Done?

Database migration is a multi-stage process involving some or all of the following steps:

1. Assessment

At this stage, you need to collect business requirements, evaluate costs and benefits, and perform data analysis. Data analysis is the process by which you understand the existing data and database architecture. You also need to plan how to move the data-will you use ETL (Extract, Transform and Load) tools, scripts, or some other tool to move the data?

2. Database Schema Conversion

The schema is the blueprint of the database structure, which changes according to the rules of a given database. When you move data from one system to another, you need to transform the schema so that the data structure is suitable for the new database.

3. Data Migration

After completing all the preliminary requirements, you need to actually move the data. This may involve writing scripts, using ETL tools, or some other tool to move data. During the migration process, you may convert data, standardize data types, and check for errors.

4. Test and Adjust

After moving the data, you need to verify the data: the movement is correct, complete, has no missing values, does not contain null values, and is valid.

Best Practices for Successful Database Migrations

Successfully executing a database migration requires careful planning, attention to detail, and adherence to best practices. Consider implementing the following practices to ensure a smooth and successful database migration:

Thorough Planning and Assessment

1. Assess the need for migration and define clear goals and objectives.

2. Evaluate the risks and potential impact on business operations.

3. Develop a comprehensive migration plan, including timelines, tasks, and resources.

At this crucial stage, MigVisor by EPAM can be a helpful database migration tool. It is a cloud migration assessment product that helps companies analyze database environments and generate a visual cloud migration roadmap to accelerate database migration to the cloud.

Minimizing Downtime and Impact on Users

1. Schedule the migration during periods of low activity or implement phased migrations.

2. Set up appropriate backup and recovery mechanisms to minimize data loss.

3. Communicate with stakeholders and end-users, providing them with updates and support.

Data Validation and Quality Assurance

1. Perform a thorough analysis of the source data to identify any inconsistencies or errors.

2. Validate and clean the data before the migration process.

3. Conduct post-migration data checks to ensure data integrity in the target system.

Performance Monitoring and Optimization

1. Monitor the performance of the migrated database in the new environment.

2. Identify and address any performance bottlenecks or optimization opportunities.

3. Continuously optimize the database configuration, indexes, and queries for optimal performance.

By following these best practices, organizations can minimize risks and achieve a successful and efficient database migration that meets the desired goals and objectives.

Conclusion

Database migration is a critical process that involves migrating schema, data, and applications to a new system or environment. By understanding the types of migrations, following best practices, and leveraging appropriate database migration tools, businesses can successfully navigate the challenges and ensure a smooth transition. A well-executed database migration enables organizations to adapt to changing needs, enhance performance, and maintain data integrity, ultimately supporting their overall operational efficiency and success.