Re: Theoretical - restrict references

As I understand it:

Oracle does not start a transaction when issuing a select statement (a select statement
does not mutate any data). When a function is used in a select statement (as in
select customer_id, get_country_name( country_id ) from customers ) Oracle wants to
be guaranteed, that no updates take place in this function as it cannot provide roll-back due
to the fact that no transaction was started.

Peter.

"Doug C" <dcowles_at_i84.net> wrote in message news:jfc99tojnp2qmqlgphu0fbaullo227iqut_at_4ax.com...
> I understand that the restrict references pragma enforces that the
 function,
> procedure, etc., does not do certain things to certain tables.
>
> Can someone elaborate on what we are trying to avoid? A sort of mutating
> trigger like problem? Like selecting from a table for which we are
 updating the
> same table?
>
> Please.. all sorts of examples... interested...
>
>
> Thanks,
> D
Received on Thu Feb 22 2001 - 06:53:39 CST