The only way to accomplish this today would be to log the data using two separate historical transaction groups and combine the data using a query. Not rocket science, but also not very obvious.
We’ve been working on some improvements for the SQLTags Historian feature that should help address this idea where you want fine-grained detail but only for a short timeframe, and beyond that you accept coarser logging.
There are a few ways we want to attack this problem of variable density history. One is that we want to have generational consolidation within the SQLTags Historian. This means that as data ages, the Historian will “digest” it into a format that is coarser and more well-suited to quickly handling queries that span a long timespan.
Another feature would be age-based thinning of data, where data that was logged at a very fine resolution gets thinned out as it ages.
These two ideas are pretty similar, they may be combined into a single concept. We’re going to be improving SQLTags Historian for Ignition 7.3, and I expect that some features along these lines will be included in that release.