DataSync is middleware that sits between your PC or laptop computer and your master database. Over the network, DataSync selects and downloads precisely the data required by your remote users. Once the data is downloaded, users can disconnect from the network and access, modify, and add to the data on their individual computers, using existing applications. When a user reconnects to the network, DataSync synchronizes the user's extract of the database with the master database. DataSync does a field-by-field analysis of both databases, recognizes and merges data that has changed, bringing both copies of the database up to date. DataSync automatically keeps your data consistent, up-to-date, and under control.

DataSync performs three major functions:

1. Subset Definition. Using the DataSync Development Tool, you create a subset definition. The subset definition specifies: What portion of the master database is to be extracted for particular users and applications. How the data is to be merged and conflicts reconciled when the data is to be synchronized back into the master database. A subset definition is defined once for repeated use.
2. Subset Extraction. Based on a subset definition, a subset of the master database is downloaded into a local target database. Once downloaded over the network or other communication link, the target database can be detached and used as a mobile or standalone database.
3. Subset Merge. Changes to the extracted database are reincorporated into the master database. Conflicts are automatically reconciled as specified in the subset definition.