Open Source Solution for Database Synchronization

Some time we need solution for database synchronization/replication in application end.Databases itself provides database replication solution but it has limitation when some customization required.

Cases When This Type Of System Required

1. It could be help when limited number of tables are need synchronization functionality.
2. Offline/Online management for data synchronization.
3. Replication support needed across different combination of supported databases.
   
4. Replication needed on partial data (Tables, Rows and column can be customize).
5. etc
   

Thanks to open source community for providing us solution for this specific problems too.I only mention two open source solutions which I explore little bit.

SymmetricDS - SymmetricDS is a web based/Standalone service/Embedded application, database independent, data synchronization system. Beyond replicating tables between relational databases the software incorporates functionality to handle a large number of databases, manage low-bandwidth connections and work within periods of network outage. The system supports two way replication, guaranteed delivery and multiple active schemas.

Daffodil Replicator - Daffodil Replicator performs data replication based on the 'Publish and Subscribe' model. Replicator supports bi-directional data replication by either capturing a data source snapshot or synchronizing the changes. It monitors data changes, synchronizes all data changes on periodic basis or on-demand. Replicator can use pre-defined conflict resolution algorithms to resolve conflicts between data sources.