Comment by refset

The upcoming XTDB v2 is a SQL-first engine. We also built an experimental Clojure/Datalog-like 'XTQL' language to go along with it, to provide some continuity for v1 users, but the primary API is now SQL over the Postgres wire protocol, where we implemented a variation on SQL:2011 - see https://docs.xtdb.com/quickstart/sql-overview.html