SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 3)
   ExpressionList (children 1)
    Function greater (children 1)
     ExpressionList (children 2)
      Identifier a
      Literal UInt64_0
   TablesInSelectQuery (children 1)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      TableIdentifier optimize_sorting
   Function greater (children 1)
    ExpressionList (children 2)
     Identifier a
     Literal UInt64_0
