Re: Can a C function(server program) be a UDP or TCP server?

On Thu, 18 Oct 2007 11:24:24 -0400
"Billow Gao" <billowgy@gmail.com> wrote:
> I can write the network program.
> But I am not 100% sure whether I can add the c-language function (
> http://www.postgresql.org/docs/8.2/interactive/xfunc-c.html)
> to PostgreSQL. The function will be dynamic loaded by PostgreSQL.
> I want to know whether there are any limitation on the function I wrote.
> 
> for example:
> If I want to write a function:
> 
> PG_FUNCTION_INFO_V1(c_talktoremoteudp);
> 
> 
> And use it in PostgreSQL like:
> 
> =========================================
> SELECT name, c_talktoremoteudp
> 
> (emp, 1500) AS overpaid
>     FROM emp
>     WHERE name = 'Bill' OR name = 'Sam';
> 
> =========================================
> The function c_talktoremoteudp will:
> 1. send udp data to remote udp server
> 2. monitor an udp port and wait for the reply
> 3. return the data to the select query.

I am confused.  The dynamic function resides in the server.  The query
runs in the server.  Where is the "remoteness" in any of this?  Are you
saying that there is a second server that is not PostgreSQL that uses
UDP that you want to communicate with and merge info into the
PostgreSQL server from?

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