Обсуждение: how to create dir using pg/plsql

just subject,

i need to create dir using pg/plsql function,,but cannt get anything after google,

please advise? thanks!

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On Wed, Aug 29, 2007 at 02:45:56PM +0800, qinghuamail-postgresqlfans@yahoo.com wrote:
> just subject,
> i need to create dir using pg/plsql function,,but cannt get anything after google,

it's not possible.
pl/pgsql is trusted language (like pl/perl and pl/tcl). trusted
languages cannot use system-level functions. so no file, directory,
socket access is possible.

depesz

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oh,i see, thank you very much!

hubert depesz lubaczewski <depesz@depesz.com> 写道：

On Wed, Aug 29, 2007 at 02:45:56PM +0800, qinghuamail-postgresqlfans@yahoo.com wrote:
> just subject,
> i need to create dir using pg/plsql function,,but cannt get anything after google,

it's not possible.
pl/pgsql is trusted language (like pl/perl and pl/tcl). trusted
languages cannot use system-level functions. so no file, directory,
socket access is possible.

depesz

--
quicksil1er: "postgres is excellent, but like any DB it requires a
highly paid DBA. here's my CV!" :)
http://www.depesz.com/ - blog dla ciebie (i moje CV)

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On 8/29/07, qinghuamail-postgresqlfans@yahoo.com
<qinghuamail-postgresqlfans@yahoo.com> wrote:
> just subject,
>
> i need to create dir using pg/plsql function,,but cannt get anything after
> google,

As noted, not possible.  BUT, you can do it in untrusted languages,
like pl/perlu or pl/tclu or pl/C

I was under the impression that recent modern databases, like PG, allow you to transfer  control to an out-of-system (system being the DB engine) module (shared lib, dll). That is while triggers transfer control within the system, now mechanisms exists that allow you to go outside of the system. In that context, whence the control is transferred to a C, Perl or whatever language, who is to stop that function from doing anything it wants.

I appreciate a clarification.

Medi

"Medi Montaseri" <montaseri@gmail.com> writes:
> I was under the impression that recent modern databases, like PG, allow you
> to transfer  control to an out-of-system (system being the DB engine) module
> (shared lib, dll). That is while triggers transfer control within the
> system, now mechanisms exists that allow you to go outside of the system. In
> that context, whence the control is transferred to a C, Perl or whatever
> language, who is to stop that function from doing anything it wants.

Well, sure.  Postgres calls those untrusted languages, and only lets
database superusers use them.

            regards, tom lane

I see...thank you for the clarification...one more question...
How does PG protects itself from a run-away code (eg an endless loop) ? In other words, does PG run the "untrusted" code in a seperate process?

Thanks
Medi

Medi Montaseri escribió:
> I see...thank you for the clarification...one more question...
> How does PG protects itself from a run-away code (eg an endless loop) ?

It doesn't.

> In other words, does PG run the "untrusted" code in a seperate
> process?

No.

--
Alvaro Herrera                                http://www.CommandPrompt.com/
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