What is Database Migration?
Database migration refers to the process of transferring data between different types of database management systems (DBMS), storage formats, or computing environments. It involves moving data from one system to another while ensuring data integrity, consistency, and security.
The following defines key terms related to database migration:
ETL (Extract, Transform, Load)
ETL is a process used in database migration to extract data from the source database, transform it to fit the target database’s schema or requirements, and then load it into the destination database.
Source Database
The source database is the database from which data is being migrated. It can be any type of database system such as MySQL, PostgreSQL, Oracle, SQL Server, etc.
Target Database
The target database is the database to which data is being migrated. It can also be any type of database system, and it may or may not be the same as the source database.
Schema Mapping
Schema mapping involves mapping the structure and relationships of data objects (tables, columns, etc.) from the source database to the target database. It ensures that data is properly transformed and loaded into the new database schema.
Data Migration Tools
Data migration tools are software applications or utilities specifically designed to facilitate database migration tasks. These tools often provide features such as schema mapping, data transformation, validation, and scheduling to streamline the migration process.
Data Integrity
Data integrity refers to the accuracy, consistency, and reliability of data during and after the migration process. Ensuring data integrity is crucial to maintain the quality and reliability of the migrated data.
Testing and Validation
Testing and validation involve verifying the accuracy and completeness of migrated data through various methods such as data profiling, comparison, and validation against predefined criteria. It helps identify and rectify any issues or discrepancies in the migrated data.
Rollback Plan
A rollback plan is a contingency plan put in place to revert the database migration process to its original state in case of any unforeseen issues, errors, or failures during migration. It ensures minimal disruption and data loss in case of migration failures.
Downtime
Downtime refers to the period during which the database or applications accessing the database are unavailable or inaccessible to users. Minimizing downtime is a key consideration in database migration to reduce business disruptions and ensure continuity of operations. It’s possible to limit or eliminate downtime by running a multi-step migration where new data is written to the original source database and the new target database simultaneously, while still only reading from the source database for production users. Parity testing can then be performed to ensure that the target database returns equivalent responses before the source database is retired.
Data Synchronization
Data synchronization involves keeping data consistent and up-to-date between the source and target databases during and after migration. It may involve ongoing replication or synchronization mechanisms to ensure data consistency across environments.
Data Migration Strategy
A data migration strategy is a comprehensive plan outlining the approach, methodologies, tools, resources, and timelines for executing database migration projects. It encompasses various aspects such as risk assessment, data profiling, migration planning, execution, and post-migration support.
