SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 1)
   ExpressionList (children 1)
    Function substringIndex (children 1)
     ExpressionList (children 3)
      Function materialize (children 1)
       ExpressionList (children 1)
        Literal \'www.clickhouse.com\'
      Literal \'.\'
      Function materialize (children 1)
       ExpressionList (children 1)
        Literal UInt64_4
