In the context of product licensing, "data retention" refers to the guaranteed retention period of the performance metrics in the Kadiska platform database. It determines how far in the past you can request performance data related to your tenant/organization.
Older data are not aggregated as it is often the case in many monitoring solutions.
It means that Kadiska always keeps the full data granularity, independently of the requested time and related duration.
So according to your subscription plan, you may request up to 90 days of full granular data, including all sessions detailed views like Waterfalls!