Re: PENDING_LIST_CLEANUP_SIZE - maximum size of GIN pending list Re: HEAD seems to generate larger WAL regarding GIN index

(2014/10/08 22:51), Fujii Masao wrote:
> On Wed, Sep 24, 2014 at 11:10 AM, Etsuro Fujita
> <fujita(dot)etsuro(at)lab(dot)ntt(dot)co(dot)jp> wrote:

>>> On Wed, Sep 10, 2014 at 10:37 PM, Alvaro Herrera
>>> <alvherre(at)2ndquadrant(dot)com> wrote:
>>>> Fujii Masao wrote:
>>>>> On Wed, Sep 10, 2014 at 12:15 PM, Etsuro Fujita
>>>>> <fujita(dot)etsuro(at)lab(dot)ntt(dot)co(dot)jp> wrote:

>>>>>> PENDING_LIST_CLEANUP_SIZE and work_mem, for this setting.
>>>>>> Wouldn't it be easy-to-use to have only one parameter,
>>>>>> PENDING_LIST_CLEANUP_SIZE? How about setting PENDING_LIST_CLEANUP_SIZE
>>>>>> to
>>>>>> work_mem as the default value when running the CREATE INDEX command?

>>>>> So what about introduing pending_list_cleanup_size also as GUC?
>>>>> That is, users can set the threshold by using either the reloption or
>>>>> GUC.

>>>> Yes, I think having both a GUC and a reloption makes sense -- the GUC
>>>> applies to all indexes, and can be tweaked for individual indexes using
>>>> the reloption.

>> OK, I'd vote for your idea of having both the GUC and the reloption. So, I
>> think the patch needs to be updated. Fujii-san, what plan do you have about
>> the patch?

> Please see the attached patch. In this patch, I introduced the GUC parameter,
> pending_list_cleanup_size. I chose 4MB as the default value of the parameter.
> But do you have any better idea about that default value?

It seems reasonable to me that the GUC has the same default value as
work_mem. So, +1 for the default value of 4MB.

> BTW, I moved the CommitFest entry of this patch to next CF 2014-10.

OK, I'll review the patch in the CF.

Thanks,

Best regards,
Etsuro Fujita