Explain EXPLAIN SYNTAX (children 1)
 InsertQuery   (children 3)
  Literal \'data.file\'
  Identifier test
  SelectWithUnionQuery (children 1)
   ExpressionList (children 1)
    SelectQuery (children 2)
     ExpressionList (children 1)
      Identifier x
     TablesInSelectQuery (children 1)
      TablesInSelectQueryElement (children 1)
       TableExpression (children 1)
        Function input (children 1)
         ExpressionList (children 1)
          Literal \'x UInt32\'