Datalog is a deductive query system combining a database of facts (the Datomic db) with a set of rules for deriving new facts from existing facts and other rules. This query capability is combined with a powerful hierarchical selection facility, so you can recover tree-like data without joins or complex re-assembly. Datalog with negation is of equivalent power to relational algebra with recursion. Datalog is a great fit for application queries thanks to:
Pattern-matching like structure, in which joins are implicit
Recursion is much more straightforward than in SQL
Datalog rules subsume SQL views, but have more of a logic feel, allowing a closer alignment to business rules
