Data Migration is the process of transferring data between storage types, formats, or computer systems. Data migration is usually performed programmatically to achieve an automated migration, freeing up human resources from tedious tasks. It is required when organizations or individuals change computer systems or upgrade to new systems.
Database migration
Database may be necessary to move from one database vendor to another, or to upgrade the version of database software being used. The latter case is less likely to require a physical data migration, but this can happen with major upgrades. In these cases a physical transformation process may be required since the underlying data format can change significantly. This may or may not affect behaviour in the applications layer, depending largely on whether the data manipulation language or protocol has changed - but modern applications are written to be agnostic to the database technology so that a change from Oracle to MySQL, DB2 or SQL Server should only require a testing cycle to be confident that both functional and non-functional performance has not been adversely affected.
Application migration
Changing application vendor - for instance a new CRM or ERP platform will inevitably involve substantial transformation as almost every application or suite operates on its own specific data model. Further, to allow the application to be sold to the widest possible market, commercial off-the-shelf packages are generally configured for each customer using metadata. Application programming interfaces (APIs) are supplied to protect the integrity of the data they have to handle. Use of the API is normally a condition of the software warranty, although a waiver may be allowed if the vendor's own or certified partner professional services and tools are used.
