AlterQuery  v (children 2)
 ExpressionList (children 1)
  AlterCommand MODIFY_QUERY (children 1)
   SelectWithUnionQuery (children 1)
    ExpressionList (children 1)
     SelectQuery (children 2)
      ExpressionList (children 1)
       Literal NULL (alias x)
      TablesInSelectQuery (children 1)
       TablesInSelectQueryElement (children 1)
        TableExpression (children 1)
         TableIdentifier src
 Identifier v
