Re: [HACKERS] an older problem? hash table out of memory

Bruce Momjian <maillist(at)candle(dot)pha(dot)pa(dot)us> writes:
>> The "hashtable out of memory" problem is reproducible, however.
>> I'm on it.

> Historically, no one knows much about the hash routines.

Well, I've been learning some unpleasant truths :-(. Hope to have
some fixes to commit in the next few days.

The immediate cause of one coredump I saw was that someone who was
overenthusiastically replacing sprintf's with snprintf's had written

snprintf(tempname, strlen(tempname), ...);

where tempname points to just-allocated, quite uninitialized
memory. Exercise for the student: how many different ways can
this go wrong? Unsettling question: how many other places did
that someone make the same mistake??

I don't have time for this right now, but it'd be a real good idea
to grep the source for strlen near snprintf to see if this same
problem appears anywhere else...

regards, tom lane