Re: Reviewing freeze map code

On Sat, Jun 4, 2016 at 1:46 PM, Masahiko Sawada <sawada.mshk@gmail.com> wrote:
> On Sat, Jun 4, 2016 at 12:59 AM, Robert Haas <robertmhaas@gmail.com> wrote:
>> On Fri, Jun 3, 2016 at 11:21 AM, Masahiko Sawada <sawada.mshk@gmail.com> wrote:
>>>> Can you submit that part as a separate patch?
>>>
>>> Attached.
>>
>> Thanks, committed.
>>
>>>>> I'm address the review comment of 7087166 commit, and will post the patch.
>>>>
>>>> When?
>>>
>>> On Saturday.
>>
>> Great.  Will that address everything for this open item, then?
>>
>
> Attached patch for commit 7087166 on another mail.
> I think that only the test tool for visibility map is remaining and
> under the discussion.
> Even if we have verification tool or function for visibility map, we
> cannot repair the contents of visibility map if we turned out that
> contents of visibility map is something wrong.
> So I think we should have the way that re-generates the visibility map.
> For this purpose, doing vacuum while ignoring visibility map by a new
> option or new function is one idea.
> But IMHO, it's not good idea to allow a function to do vacuum, and
> expanding the VACUUM syntax might be somewhat overkill.
>
> So other idea is to have GUC parameter, vacuum_even_frozen_page for example.
> If this parameter is set true (false by default), we do vacuum whole
> table forcibly and re-generate visibility map.
> The advantage of this idea is that we don't necessary to expand VACUUM
> syntax and relatively easily can remove this parameter if it's not
> necessary anymore.
>

Attached is a sample patch that controls full page vacuum by new GUC parameter.

Regards,

--
Masahiko Sawada