Tomas Vondra <tomas.von...@2ndquadrant.com> writes:
> On Wed, Jun 24, 2020 at 01:29:56PM -0400, Tom Lane wrote:
>> If we feel we need something to let people have the v12 behavior
>> back, let's have
>> (1) enable_hashagg on/off --- controls planner, same as it ever was
>> (2) enable_hashagg_spill on/off --- controls executor by disabling spill
> What if a user specifies
> enable_hashagg = on
> enable_hashagg_spill = off
It would probably be reasonable for the planner to behave as it did
pre-v13, that is not choose hashagg if it estimates that work_mem
would be exceeded. (So, okay, that means enable_hashagg_spill
affects both planner and executor ... but ISTM it's just one
behavior not two.)
regards, tom lane
