Automatic Resolution of Collisions
With automatic resolution, when two records collide, one record prevails over the other. If the operation was an insert or an update, a record survives a collision by overwriting the record in the target database (the target row is deleted and the prevailing source row is inserted in its place). If the transaction was a delete, the record in the target database is deleted. If a record does not survive a collision, its replication operation (insert, update, or delete) for that target is removed from the distribution queue.
Note: Automatic resolution overwrites the entire record and can overwrite columns that have correct information with columns that do not have correct information. You must not use automatic resolution if the information contained in the losing record is important. For example, if your database contains documents that are continually updated with new information, you can lose information with automatic resolution.