[refset]

> that lets you query through time (also called "Bitemporal modeling" with fancier words)

Datomic is actually only 'uni-temporal', it provides a database-wide, immutable "system time" (aka "transaction time") versioning + very effective as-of querying. This naturally falls out of the "Epochal Time Model" (see Deconstructing the Database, 2012). However there is no particular built-in support for any further mutable time dimension, see: https://vvvvalvalval.github.io/posts/2017-07-08-Datomic-this...

System-time is still very powerful though. The way I think of the difference is: system-time versioning is mainly useful for debugging and auditing (and of course for the horizontal read scaling), whereas valid-time versioning is useful for timestamp-based reporting (or other forms of in-application time-travel and modelling 'truth' in business data) where the system-time timestamps are not the timestamps end users are directly interested in, see: https://tidyfirst.substack.com/p/eventual-business-consisten...