For some time now we have published various examples of how to replicate ISAM data to a relational database such as SQL Server in near to real time. Until now however, all of these examples have required that the ISAM files that were to be replicated needed be modified by the addition of a new “replication key” field and the addition of a corresponding key in the file. Generally this new field and key would be populated with a timestamp value that was unique to each record in the file. While this technique guarantees that every ISAM file can be replicated, it also made it hard work to do so because the record layout and key configuration of each ISAM file needed to be changed.

However, almost all ISAM files already have at least one unique key, and when that is the case one of those existing those keys could be used to achieve replication without requiring changes to the original record layouts or files. When this technique is combined with the capabilities of I/O hooks it is now possible to achieve data replication with only minimal effort, often with no changes to the ISAM files being replicated, and with only minimal modification of the original application code.

I am pleased to announce that I have just published a new example of doing exactly that. You can find the example code on GitHub at https://github.com/SteveIves/SqlReplicationIoHooks. Of course if you are interested in implementing data replication to a relational database but need some assistance in doing so, then we’re here to help; just contact your Synergex account manager for further information.