Does that mean I can't make a function in C that will have all the database transactions and then would just be included in the Stored Procedure in postgres (though i know there is no concept of stored procs in postgres, its all functions that you have in it).
If this is not the case then i think its just a normal function that'll have some sort of business logic and would be included in a postgres function instead of writing that function in postgres itself.
Please correct me if I am wrong and please add some more knowledge here so that my doubts are clearified.
Also when i say include <postgres.h>, my function would not find it coz its in some different path altogether. Where exactly is this postgres.h and other postgres header files??
Regards,
~Jas
On 6/20/06, Michael Fuhr <mike@fuhr.org> wrote:[Please copy the mailing list on replies so others can participate
in and learn from the discussion.]
On Tue, Jun 20, 2006 at 11:39:03AM -0400, Jasbinder Bali wrote:
> Well, as in normal Sql server or oracle Stored procedures, you write a
> procedure in the database server and some middle tier would invoke it.
> Now here what is the concept of server side or client side function in
> postres if i just have to create a function in C and then would like my
> Stored procedure to invoke it. Also all the DB related activities like
> select, delete, update should be taken care of by the C function itself.
It sounds like you want to write a server-side function that a
client application or another server-side function could invoke
with SELECT do_stuff() (or PERFORM do_stuff() in PL/pgSQL). You
can do that in C, but unless you need the kind of low-level
functionality that only C can provide then you'd probably be better
off using a higher level server-side language like PL/pgSQL, PL/Perl,
PL/Python, PL/Tcl, PL/Ruby, PL/Java, PL/R, etc.
Functions in PostgreSQL aren't the same as stored procedures in
some other DBMSs. For example, a function can't start or end a
transaction since it's already being executed in the context of a
transaction, although in 8.0 and later a function can do partial
rollbacks via exception handling. However, a function could connect
to the database via dblink, Perl DBI, etc., and then do anything
that an ordinary client could do.
--
Michael Fuhr