Hiya
I have written a trigger in C, and during the course of this I
discovered that the LOAD command in psql wasn't updating the object when
I made a change and recompiled.
As requested by Tom, here is an example of this behaviour. I have just
added this as a function as it performs the same.
here is my code:
--START--
#include "postgres.h"
#include "executor/spi.h" /* this is what you need to work with
SPI */
#include "commands/trigger.h" /* ... and triggers */
#include <stdio.h>
int main (int argc, char **argv)
{
printf ("This is a trigger for PostgreSQL, not a standard
executable\n\n");
return 0;
}
extern Datum trigf(PG_FUNCTION_ARGS);
PG_FUNCTION_INFO_V1(trigf);
Datum testtrig(PG_FUNCTION_ARGS)
{
TriggerData *trigdata = (TriggerData *) fcinfo->context;
elog(INFO,"This is a test trigger");
//elog(INFO,"Uncomment me and recompile for new message");
return PointerGetDatum(NULL);
}
--END--
I have compiled and linked this with the lines:
gcc -g -c test_trigger.c -I/usr/include/pgsql/server
gcc -o testtrigger test_trigger.o --share
without errors.
to create the function I used:
create or replace function testtrig() RETURNS trigger AS
'/home/graeme/dev/radius-centraldb/testtrigger' LANGUAGE C;
Now when I "select testtrig();" I get :
INFO: This is a test trigger
ERROR: Cannot display a value of type TRIGGER
If I uncomment out the 2nd elog line and recompile and then use
LOAD '/home/graeme/dev/radius-centraldb/testtrigger';
Again running "select testtrig()" I get :
INFO: This is a test trigger
ERROR: Cannot display a value of type TRIGGER
So the new Object hasn't been loaded (I know about the Error on the end,
this is just a quick test).
If I quit out of psql and reconned, and then run "select testtrig()" I
now get:
INFO: This is a test trigger
INFO: Uncomment me and recompile for new message
ERROR: Cannot display a value of type TRIGGER
So as you can see it doesn't appear to be refreshing the C object when I
use LOAD. I also noticed during writing the C for this example that if
I created the function with the wrong name I got an error saying that
that function could not be found in the object as is expected, if I then
renamed the function and recompiled the object, the create would give
the same error (obviously using the already linked object). Load didn't
fix this either.
So am I doing something wrong? or have I found something?
Thanks for your help/time
--
-----
Graeme Hinchliffe (BSc)
Core Internet Systems Designer
Zen Internet (http://www.zen.co.uk/)
Direct: 0845 058 9074
Main : 0845 058 9000
Fax : 0845 058 9005