Re: 9.5: Better memory accounting, towards memory-bounded HashAgg

On Mon, Dec 8, 2014 at 9:39 AM, Michael Paquier
<michael.paquier@gmail.com> wrote:
> On Tue, Dec 2, 2014 at 2:14 PM, Jeff Davis <pgsql@j-davis.com> wrote:
>> On Sun, 2014-11-30 at 17:49 -0800, Peter Geoghegan wrote:
>>> On Mon, Nov 17, 2014 at 11:39 PM, Jeff Davis <pgsql@j-davis.com> wrote:
>>> > I can also just move isReset there, and keep mem_allocated as a uint64.
>>> > That way, if I find later that I want to track the aggregated value for
>>> > the child contexts as well, I can split it into two uint32s. I'll hold
>>> > off any any such optimizations until I see some numbers from HashAgg
>>> > though.
>>>
>>> I took a quick look at memory-accounting-v8.patch.
>>>
>>> Is there some reason why mem_allocated is a uint64? All other things
>>> being equal, I'd follow the example of tuplesort.c's
>>> MemoryContextAllocHuge() API, which (following bugfix commit
>>> 79e0f87a1) uses int64 variables to track available memory and so on.
>>
>> No reason. New version attached; that's the only change.
> Note that I am marking this patch back to "Needs Review" state. I
Moving to CF 2014-12.
-- 
Michael