Explain EXPLAIN SYNTAX (children 1)
 SelectWithUnionQuery (children 1)
  ExpressionList (children 1)
   SelectQuery (children 3)
    ExpressionList (children 1)
     Identifier number
    TablesInSelectQuery (children 1)
     TablesInSelectQueryElement (children 1)
      TableExpression (children 1)
       Subquery (children 1)
        SelectWithUnionQuery (children 1)
         ExpressionList (children 1)
          SelectQuery (children 4)
           ExpressionList (children 1)
            Identifier number
           TablesInSelectQuery (children 1)
            TablesInSelectQueryElement (children 1)
             TableExpression (children 1)
              TableIdentifier t
           ExpressionList (children 1)
            OrderByElement (children 1)
             Identifier number
           Literal UInt64_3
    Function less (children 1)
     ExpressionList (children 2)
      Identifier number
      Literal UInt64_18
