LOAD not updating object in session
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
Graeme Hinchliffe <graeme.hinchliffe@zeninternet.co.uk> writes:
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.
Thanks for the test case. Unfortunately it works fine here:
regression=# select testtrig();
INFO: This is a test trigger
ERROR: cannot display a value of type trigger
regression=# LOAD '/home/tgl/testtrigger';
LOAD
regression=# select testtrig();
INFO: This is a test trigger
INFO: Uncomment me and recompile for new message
ERROR: cannot display a value of type trigger
regression=#
This is on RHL 8.0 on i386. What platform are you using exactly?
BTW, the file as given dumps core for me, because you have
extern Datum trigf(PG_FUNCTION_ARGS);
PG_FUNCTION_INFO_V1(trigf);
Datum testtrig(PG_FUNCTION_ARGS)
and the V1 macro needs to reference testtrig not trigf. However I do
not think this is related to the LOAD problem.
regards, tom lane
On Tue, 2004-08-17 at 17:27, Tom Lane wrote:
Graeme Hinchliffe <graeme.hinchliffe@zeninternet.co.uk> writes:
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.Thanks for the test case. Unfortunately it works fine here:
damn :) (but in a good way)
This is on RHL 8.0 on i386. What platform are you using exactly?
This is RH 9.0 on i386 from RPM's
BTW, the file as given dumps core for me, because you have
extern Datum trigf(PG_FUNCTION_ARGS);
PG_FUNCTION_INFO_V1(trigf);
Datum testtrig(PG_FUNCTION_ARGS)
oops! In the original I did have my function named as trigf, but I
changed that so as not to conflict with the other function in my db
and the V1 macro needs to reference testtrig not trigf. However I do
not think this is related to the LOAD problem.
It didn't dump core for me, it was quite happy :) I would guess because
I have a function called trigf loaded in memory?
Do you have any ideas what I am doing or what I have set wrong?
--
-----
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
Graeme Hinchliffe <graeme.hinchliffe@zeninternet.co.uk> writes:
It didn't dump core for me, it was quite happy :) I would guess because
I have a function called trigf loaded in memory?
No; the lack of a V1 macro referencing testtrig would definitely cause
the backend to call testtrig using V0 conventions, in other words fcinfo
will not be passed. It could be that the indirection through a garbage
value of fcinfo happens to land on valid memory in your compilation.
(I did not get a core dump either when compiling on HPUX, but I have not
bothered to chase down why not.)
I don't know of any reason for RHL 9 to work differently from RHL 8 in
this regard. Can anyone else duplicate the problem?
BTW, given the testtrig/trigf confusion ... is it possible you were
LOADing the wrong file?
regards, tom lane