Progress
Programming
Handbook


Detecting and Capturing Data Collision

Data collision results under the following conditions:

  1. User 1 updates a record in database A.
  2. User 2 updates the same record in database B.
  3. The record is replicated from database A to database B, or from B to A.

Data collision is a crucial issue you must address in replication, particularly in an asynchronous implementation with peer-to-peer user updating.

To maintain data integrity, data collisions must be addressed transaction by transaction. Addressing data collision involves detection and resolution. To address data collisions you might apply the following strategy:

  1. Detect collisions by comparing the records in the replication change logs for the respective sites. When there is a collision, isolate all records associated with the transactions in a collision log.
  2. Analyze records in the collision log. If necessary, determine the differences between records down to the field level.
  3. Resolve the collisions and propagate the results.

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