There are few components in the Elastic stack, which I'm not sure I understand the difference and when to use which.
for ML I use (currently) datafeed with pre-defined query (in practice it seems to aggregate metrics by a given time frame)
Rollup adds a functionality for aggregate raw indices and save query time/ space..
And in the latest version, after upgrading from 6.7 to 7.5, there is a new feature called 'data frames', which sounds similar..
So.. if my purpose is to aggregate data into smaller indices which can accept queries, and also run ML jobs. which should I choose, and why there are few features with similar functionality?