What are the differences between Database synchronization and replication

What are the differences between Database synchronization and replication?
Posted by: Pervasync Software ()
Date: January 02, 2009 04:14PM

Database synchronization is closely related to database replication. In fact, sometimes people use the terms interchangeably. However, there are big differences, understanding which will help us understand the different approaches used for solving replication and synchronization problems.

Replication is mostly used in situations where identical replicas of the complete data set are maintained on two or more database instances for high availability and performance reasons. Database instances can often work independently as backups for each other. The relationships between the instances are equal, symmetric. Normally the number of DB instances is small.

On the other hand, in a database synchronization system, typically you have a big central database on the server side and a large number of small databases each residing on a device. The central database contains data for all the devices while each device’s local database only contains the device’s private data and some shared data.

In the non-database world, Synchronization is also often used to describe the data exchange between a more temporal sub-set of data and a more persistent full-set of data. For instance, parts of a file could be buffered in-memory by an operating system and are “synchronized” with the file on hard disk. Another example is the synchronization of the data in a CPU cache memory with the data in the main memory.

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