For those curious on what the heck datomic is, I found this podcast helpful: http://thinkrelevance.com/blog/2012/04/26/thinkrelevance-the... The key to me is that you can run multiple queries against the same point in time, thereby having a sound basis for the data you are working with. Compare this to working with traditional RDBMS having to get it all done in a single query to have a coherent view of the world, or…
How is this different than isolation / repeatable reads in SQL transactions?
a) It can occur over time and place - i.e. I can communicate a basis point (tiny, a long) to you, and 3 days later you can look at exactly what I saw
b)It doesn't require any coordination, read locks, MVCC etc