Alex - to log to the same format, you would have two options (and a half): set up transaction groups that map to that format (the half option: write a stored procedure and map groups to it), or use updatable views to map to mimic sqltags history and map across.
The simplest option, in my opinion, is to use SQLTags History and just log data separately. But, having data twice isn’t the greatest solution, and a lot depends on how much you want to integrate in old data.
If you were going to use transaction groups and map them, I suppose you might as well map to the old format, though there may be some difficulty with the idea of tag ids. Also, setting this up with transaction groups could be a little more work than you’d want which gets me to…
AutomationNC - In one scenario, you would have a tag per group. This would really not be desirable though due to the weight of each group and work of configuring. A second option, which is better but slightly less flexible is to use Block Groups. These have a mode that will “insert changed rows”. You would create a block item for the tag path, the value, quality, and timestamp.
This comes up from time to time and we have some ideas of how to make this easier with the transaction groups. We have lots ideas for the SQL Bridge module in general, hopefully we can get around to working on the next version soon.