explain

# File activerecord/lib/active_record/connection_adapters/mysql/database_statements.rb, line 31
        def explain(arel, binds = [])
          sql     = "EXPLAIN #{to_sql(arel, binds)}"
          start   = Concurrent.monotonic_time
          result  = exec_query(sql, "EXPLAIN", binds)
          elapsed = Concurrent.monotonic_time - start

          MySQL::ExplainPrettyPrinter.new.pp(result, elapsed)
        end