Recently a customer presented me with the following challenge: they wanted data to be synchronized from HQ to a remote site and in both ways. But they had one big limitation. There was only budget for Standard Edition of the Oracle database. That ruled out a lot of Enterprise Edition features and separately licensed options like Advanced Queueing, Streams and advanced features of materialized views. Even Oracle Golden Gate would be too expensive in the customer’s situation. So a hand built mechanism is provided by Transfer Solutions.
Overview
At HQ data is stored in several Oracle tables. These modifications are logged in a send table. On regular intervals this send table is read from the remote site. The data is copied and applied to the database at remote. This process is equally implemented for metadata from remote on the HQ site. Due to a network latency of 200ms both sites have their own system. These systems have to be synchronized at all times.
In the next figure an overview of the mechanism is shown. (meer…)