SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 3)
   ExpressionList (children 2)
    Identifier a
    Function sipHash64 (children 1)
     ExpressionList (children 2)
      Identifier a
      Literal \'a\'
   TablesInSelectQuery (children 1)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      TableIdentifier optimize_sorting
   ExpressionList (children 1)
    OrderByElement (children 1)
     Function sipHash64 (children 1)
      ExpressionList (children 2)
       Identifier a
       Literal \'a\'
