Asymmetric Migrations

Just as asymmetric replication, migration operates on exactly the same definitions. After scripting empty DB and after automatic inserting of the system tables and some user tables can be started data migration from the original system.

One of the main advantages lies in the uninterrupted work of the company. Interruption of work is only in the moment of introducing the system support to the original DB that could be captured data changes. Then there is enough time to migrate from a copy of the original DB. If it is hundreds of millions records, the migration process can be quite challenging. It depends mainly on the asymmetry data. From experience, when migrating quarter of a billion records, to be expected migration time for about fifty hours.

During the preparation of the new DB users make changes to the original DB, these changes are, however, captured in history. After putting new DB into operation is executed the first synchronization that pushes the changes to the new DB and data are balanced. Both systems can then apply the changes, these are replicated each other and both systems behave as one system.