Datomic d / as-of is really slow, how can it be improved?

I'm trying to get a Datomic database (free version 0.9.5359) as it was at a certain point in time using:

(-> conn d/db (d/as-of (Date. at-epoch)))

      

        
        
        
      

    

but it takes a REALLY long time, almost 45 seconds in some cases. Is this expected for large datasets (I have about 2GB of data)? Will using Datomic Pro make this operation faster? Any other tweaks or things that should be considered to improve this particular operation?