ash; at the price of performing new parse analysis and
    constructing a new execution plan on every execution.
   </P
><P
>     The mutable nature of record variables presents another problem in this
     connection.  When fields of a record variable are used in
     expressions or statements, the data types of the fields must not
     change from one call of the function to the next, since each
     expression will be analyzed using the data type that is present
     when the expression is first reached.