Re: [HACKERS] postgresql-v6.5beta2.tar.gz ...

>>That is a good point, but actually I think it should not be a problem.
>>vacuum.c just does open() and immediately close() on pg_vlock; it
>>doesn't hold the file descriptor open.
>>
>>When I fixed psort.c a few weeks ago, I looked through all the other
>>direct calls of open() and fopen() in the backend.  There are still half
>>a dozen or so, but none of them open more than one file or will hold the
>>file descriptor for longer than the execution of the function they're
>>in.  So I felt it was OK to leave them alone.
>>
>>The reason it's OK is that fd.c doesn't use up all the available
>>file descriptors --- it tries to leave ten or so unused.  That's
>>necessary to ensure that library functions like dlopen() will work,
>>because they don't know anything about using fd.c's routines.
>>
>>So, the occasional short-term file opening in vacuum.c and similar
>>places should not matter.  If those do fail for lack of FDs, then the
>>*real* problem is that fd.c is not estimating correctly how many file
>>descriptors it can safely use; that's what we need to fix.
>>
>>But what I want to know right now is whether this behavior has been
>>seen with code from the last week or two.  Maybe the report is just
>>a side-effect of the FD leaks that used to exist in several places...
>
>If I correctly remember, the report was regarding 6.4.2. I will check
>if it happens with current, and report back soon.

Done. With 32/64 users and 100 transactions each, I see no problem so
far.
--
Tatsuo Ishii