Advantage Concepts
Replication provides the capability to distribute changes from tables in one database to tables in another database. Advantage Replication uses an asynchronous push implementation in order to minimize performance impact on applications and to minimize latency in the delivery of updates to target databases.
N-way replication can be accomplished by defining replication rules in each data dictionary to replicate changes to each of the other databases. Optional horizontal and vertical filters can be specified to limit replication to a subset of the data.
Transactional and referential integrity is maintained during replication. If a target database is not available, the source server will maintain updates in a queue and transmit them to the target when it becomes available. Conflict resolution can be handled by CONFLICT triggers on target tables.
Advantage Replication is not synchronization. Replication can be used to keep tables synchronized, but Advantage has no functionality that checks for differences in tables or that performs an actual synchronization operation between two tables. Replication simply acts to send updates from one table to another target table. The target table does not have to be "in sync" with the source table.
Advantage Replication currently only supports record updates in ADT and DBF tables; it does not replicate other object types. For example, if you create a new stored procedure in the source database, that stored procedure will not be replicated to the target. In addition, pack (removal of deleted records) and zap (emptying of a table) operations are not replicated.
The following terms are used in the documentation.
Replication is available in Advantage Database Server for Windows NT/2000/2003 and Linux.
The copy of Advantage Database Server at the source database must be licensed for replication (contact your Advantage Sales Representative for licensing information). A separate validation code is required. Advantage Database Server at the target does not have to be licensed for replication unless it will also be replicating changes.
Advantage Database Server must be running at both the source and target locations.
A Data Dictionary is required in order to use replication. For security reasons, replication cannot be used with free connections.
See Also