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Replication strikes a balance between presenting consistent data and not depending on a single centralized location for all IS needs. 

Virtuoso offers a range of tools and technologies for replicating and synchronizing data between different servers. These technologies are suited for a wide variety of distributed IS needs, including: 

*Two-way replication of tables, involving a Virtuoso hub sharing data between a group of MS SQL Server, Oracle or DB2 databases. The Virtuoso will initiate data transfer and resolve possible update conflicts.  
*Disseminating periodically changing data between heterogeneous relational databases. Almost any ODBC/JDBC accessible database can be a source or recipient of such data.  
*Keeping Virtuoso DAV repositories in sync between Virtuoso installations.  
*Keeping Virtuoso servers in real-time sync for load balancing or hot standby situations. This is based on real-time log shipping, thus will also work for intermittently connected systems.  
*Sharing mobile data through [[SyncML]]  . The Virtuoso [[SyncML]]  server has pluggable logic for format conversions between common mobile formats such as Vcard and Vcalendar.  
All these technologies function reliably in either a constantly or intermittently connected network. Nodes will bring themselves up-to-date automatically upon reconnect or recovery, requiring minimal administration. 

A web based interface or SQL statements are used for defining publications and subscriptions and synchronization intervals. 

 [[SyncML]]  1.0 


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