Re: [HACKERS] Divide by zero error on SPARC/Linux.

>
> Hi All,
>
> In the latest CVS I can get the backend to terminate quite
> easily with a divide by 0.
>
> postgres=> select 1/0;
> pqReadData() -- backend closed the channel unexpectedly.
> This probably means the backend terminated abnormally before or while
> processing the request.
> We have lost the connection to the backend, so further processing is impossible.
> Terminating.
> [postgres(at)sparclinux pgsql]$
>
> A bt on the core shows:-
>
> I don't know if this is recently introduced behaviour or if
> it's platform dependant. I can't recall trying this before
> so maybe it's always happened on S/Linux.
>
> My immediate thought is to include a check for divide by 0
> in the intXXdiv() functions and do something like an elog(WARN,...)
>
> Firstly, what do other people get on their platform?

I get:

ttest=> select 1/0;
ERROR: floating point exception! The last floating point operation
either exceeded legal ranges or was a divide by zero

so it looks like the signal. Check these lines:

#$ gid FloatExceptionHandler
backend/postmaster/postmaster.c:1247: pqsignal(SIGFPE, FloatExceptionHandler);
backend/tcop/postgres.c:772: FloatExceptionHandler(SIGNAL_ARGS)
include/tcop/tcopprot.h:37: extern void FloatExceptionHandler(SIGNAL_ARGS);

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