2009/7/24 Tom Lane :
> I think that WindowAgg does not need any changes because it already does
> MemoryContextResetAndDeleteChildren(winstate->wincontext) at partition
> boundaries. Hitoshi, do you agree?
>
I do. Looking closer, temporal space management of Agg is getting
similar to WindowAgg's
I wrote:
> Anyway, I'll go take a look at exactly what would be involved in the
> first choice.
Actually, it seems this way results in a net *savings* of code, because
we can simply remove the code that was responsible for retail pfree'ing
of the transition values. I suppose that code must have p
Greg Stark writes:
> Rereading your diagnosis of Merlin Moncure's original problem I'm a
> bit puzzled. Why do we have to rerun the final function when we rescan
> the hash table? Surely the logical thing to do is to store the final
> value in the hash table with some flag saying that value has be
Hitoshi Harada writes:
> So two ideas from Tom seem to me a little worse than that. Modifying
> Agg.c might add overhead to reset context group by group and forcing
> array_agg() (i.e. user aggregates) to distinguish hash-mode and
> group-mode is definitely heavy for users.
I agree that the secon
2009/7/23 Greg Stark :
> On Wed, Jul 22, 2009 at 10:14 PM, Tom Lane wrote:
>> The reason for that turns out to be that we deliberately lobotomized
>> array_agg that way, just last month:
>> http://archives.postgresql.org/pgsql-committers/2009-06/msg00259.php
>> in response to this problem:
>> http:
On Wed, Jul 22, 2009 at 10:14 PM, Tom Lane wrote:
> The reason for that turns out to be that we deliberately lobotomized
> array_agg that way, just last month:
> http://archives.postgresql.org/pgsql-committers/2009-06/msg00259.php
> in response to this problem:
> http://archives.postgresql.org/pgsq
Jeff Davis writes:
> On Wed, 2009-07-22 at 17:14 -0400, Tom Lane wrote:
>> One possibility is to have nodeAgg.c reset the "aggcontext" between
>> groups when in group mode. I think this would be more than a one-liner
>> fix because it probably has pointers to transvalues that are in that
>> conte
On Wed, 2009-07-22 at 17:14 -0400, Tom Lane wrote:
> One possibility is to have nodeAgg.c reset the "aggcontext" between
> groups when in group mode. I think this would be more than a one-liner
> fix because it probably has pointers to transvalues that are in that
> context, but it's surely doable
I looked into Chris Spotts' recent report of massive memory leakage in
8.4, in a case involving array_agg() executed in a GROUP BY query:
http://archives.postgresql.org/pgsql-general/2009-07/msg00858.php
The reason for that turns out to be that we deliberately lobotomized
array_agg that way, just l
