Re: [HACKERS] Report the number of skipped frozen pages by manual VACUUM

On Wed, Mar 15, 2017 at 7:51 PM, Masahiko Sawada <sawada.mshk@gmail.com> wrote:
> On Wed, Mar 15, 2017 at 1:09 PM, Yugo Nagata <nagata@sraoss.co.jp> wrote:
>> On Fri, 10 Mar 2017 20:08:42 +0900
>> Masahiko Sawada <sawada.mshk@gmail.com> wrote:
>>
>>> On Fri, Mar 10, 2017 at 3:58 PM, Jim Nasby <jim.nasby@openscg.com> wrote:
>>> > On 3/6/17 8:34 PM, Masahiko Sawada wrote:
>>> >>
>>> >> I don't think it can say "1 frozen pages" because the number of
>>> >> skipped pages according to visibility map is always more than 32
>>> >> (SKIP_PAGES_THRESHOLD).
>>> >
>>> >
>>> > That's just an artifact of how the VM currently works. I'm not a fan of
>>> > cross dependencies like that unless there's a pretty good reason.
>>>
>>> Thank you for the comment.
>>> Agreed. Attached fixed version patch.
>>
>> It seems that it says "frozen pages" if pinskipped_pages is not zero,
>> rather than about frozenskipped_pages.
>>
>> How about writing as below?
>>
>>     appendStringInfo(&buf, ngettext("Skipped %u page due to buffer pins, "
>>                                     "Skipped %u pages due to buffer pins, ",
>>                                     vacrelstats->pinskipped_pages),
>>                      vacrelstats->pinskipped_pages);
>>     appendStringInfo(&buf, ngettext("%u frozen page.\n", "%u frozen pages.\n",
>>                                     vacrelstats->frozenskipped_pages),
>>                      vacrelstats->frozenskipped_pages);
>>
>
> Yeah, you're right. I've attached the updated version patch
> incorporated your comment and fixing documentation.

The patch looks very simple and good to me.
Barring objection, I will commit this.

Regards,

-- 
Fujii Masao