Re: HEAD seems to generate larger WAL regarding GIN index

Fujii Masao <masao.fujii@gmail.com> writes:
> On Tue, Apr 1, 2014 at 1:41 AM, Robert Haas <robertmhaas@gmail.com> wrote:
>> Should we try to install some hack around fastupdate for 9.4?  I fear
>> the divergence between reasonable values of work_mem and reasonable
>> sizes for that list is only going to continue to get bigger.  I'm sure
>> there's somebody out there who has work_mem = 16GB, and stuff like
>> 263865a48973767ce8ed7b7788059a38a24a9f37 is only going to increase the
>> appeal of large values.

> Controlling the threshold of the size of pending list only by GUC doesn't
> seem reasonable. Users may want to increase the threshold only for the
> GIN index which can be updated heavily, and decrease it otherwise. So
> I think that it's better to add new storage parameter for GIN index to control
> the threshold, or both storage parameter and GUC.

Yeah, -1 for a GUC.  A GIN-index-specific storage parameter seems more
appropriate.  Or we could just hard-wire some maximum limit.  Is it
really likely that users would trouble to set such a parameter if it
existed?
        regards, tom lane