Data Migration is the process of transferring data from one system to
another while changing the storage, database or application. In
reference to the ETL (Extract-Transform-Load) process, data migration
always requires at least Extract and Load steps.
Typically data migration occurs during an upgrade of existing hardware
or transfer to a completely new system. Examples include: migration to
or from hardware platform; upgrading a database or migrating to new
software; or company-mergers when the parallel systems in the two
companies need to be merged into one.
There are three main options to accomplish data migration: