Datomic Information Model (2013)

I know there are a few users on HN that use Datomic (including Rich Hickey).

As someone who uses a Relational database everyday, can datomic keep up performance wise with Oracle and Postgres and how long does it take to learn the non-SQL query language?

I'll add that being able to do programmatic things in your query language that SQL can't do without PL-SQL is pretty cool. I only really know of Kdb+ and Datomic that can apparently do those things. Thinking in only terms of SQL is really limiting to me.