CREATE TABLE visits (
  time     DateTime,
  visits   Nested
  (
    a          String,
    btime      Int64,
    c          String,
    e          String
  )
) ENGINE = Memory;
---------------------------
CREATE TABLE visits (
	time DateTime,
	visits NESTED (
		a String,
		btime Int64,
		c String,
		e String
	)
) ENGINE = Memory;