Re: Memory leaks in record_out and record_send

Robert Haas <robertmhaas(at)gmail(dot)com> writes:
> On Tue, Nov 13, 2012 at 12:18 AM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
>> I wonder though if we ought to think about running output functions in
>> a short-lived memory context instead of the executor's main context.
>> We've considered that before, I think, and it's always been the path
>> of least resistance to fix the output functions instead --- but there
>> will always be another leak I'm afraid.

> Such is the lot of people who code in C. I worry that the number of
> memory contexts we're kicking around already is imposing a significant
> distributed overhead on the system that is hard to measure but
> nevertheless real, and that this will add to it.

Yeah, perhaps. I'd like to think that a MemoryContextReset is cheaper
than a bunch of retail pfree's, but it's hard to prove anything without
actually coding and testing it --- and on modern machines, effects like
cache locality could swamp pure instruction-count gains anyway.

Anyway, I committed the narrow fix for the moment.

regards, tom lane