Bug #701: pqReadData() -- backend closed the channel unexpectedly.
Amit Mishra (amit.mishra@myrealbox.com) reports a bug with a severity of 2
The lower the number the more severe it is.
Short Description
pqReadData() -- backend closed the channel unexpectedly.
Long Description
i have to fire a trigger whenever insertion is done on a table users
that calls the postgres function which inturn calls a c function .
wheever i am doing the insertion in the table it gives the followng error & terminates the backend:
pqReadData() -- backend closed the channel unexpectedly.
This probably means the backend terminated abnormally
before or while processing the request.
The connection to the server was lost. Attempting reset: Failed.
i cannot find the solution to this problem .please help.
Sample Code
the c file that contains function is as follows:
#include <stdio.h>
#include "pgsql/postgres.h"
void users();
int main()
{
users();
}
void users()
{
FILE *fp;
fp = fopen("/home/suresh/trigger/test.txt","w");
fputs("Hello this is c function",fp);
}
the postgres function that calls the c function is as follows:
create FUNCTION users() returns opaque as '/var/lib/pgsql/test.so' language 'C';
the trigger that calls the postgres function is as follows:
CREATE TRIGGER users_trg before insert on users for each row execute procedure users();
No file was uploaded with this report
On Sat, 29 Jun 2002 pgsql-bugs@postgresql.org wrote:
Short Description
pqReadData() -- backend closed the channel unexpectedly.Long Description
i have to fire a trigger whenever insertion is done on a table users
that calls the postgres function which inturn calls a c function .
wheever i am doing the insertion in the table it gives the followng error & terminates the backend:pqReadData() -- backend closed the channel unexpectedly.
This probably means the backend terminated abnormally
before or while processing the request.
The connection to the server was lost. Attempting reset: Failed.i cannot find the solution to this problem .please help.
Sample Code
the c file that contains function is as follows:#include <stdio.h>
#include "pgsql/postgres.h"
void users();int main()
{
users();
}void users()
{
FILE *fp;
fp = fopen("/home/suresh/trigger/test.txt","w");
fputs("Hello this is c function",fp);
}
I don't believe this is a valid trigger function. Looking at
the trigger documentation's simple example, I think the
function should return Datum and take PG_FUNCTION_ARGS (or
technically what that expands to, but...). I also think you
need a PG_FUNCTION_INFO_V1(users); and the function should
return the new row since you're using it as a before trigger.
pgsql-bugs@postgresql.org writes:
[ this trigger crashes the backend: ]
void users()
{
FILE *fp;
fp = fopen("/home/suresh/trigger/test.txt","w");
fputs("Hello this is c function",fp);
}
Triggers are supposed to return something --- especially BEFORE
triggers. See the examples in the manual.
regards, tom lane