Re: Reviewing freeze map code

On Sun, May 8, 2016 at 3:18 PM, Masahiko Sawada <sawada(dot)mshk(at)gmail(dot)com> wrote:
> On Sat, May 7, 2016 at 11:08 PM, Masahiko Sawada <sawada(dot)mshk(at)gmail(dot)com> wrote:
>> On Sat, May 7, 2016 at 6:00 AM, Joshua D. Drake <jd(at)commandprompt(dot)com> wrote:
>>> On 05/06/2016 01:58 PM, Stephen Frost wrote:
>>>>
>>>> * Joshua D. Drake (jd(at)commandprompt(dot)com) wrote:
>>>>>
>>>>> Yeah I thought about that, it is the word "FORCE" that bothers me.
>>>>> When you use FORCE there is an assumption that no matter what, it
>>>>> plows through (think rm -f). So if we don't use FROZEN, that's cool
>>>>> but FORCE doesn't work either.
>>>>
>>>>
>>>> Isn't that exactly what this FORCE option being contemplated would do
>>>> though? Plow through the entire relation, regardless of what the VM
>>>> says is all frozen or not?
>>>>
>>>> Seems like FORCE is a good word for that to me.
>>>
>>>
>>> Except that we aren't FORCING a vacuum. That is the part I have contention
>>> with. To me, FORCE means:
>>>
>>> No matter what else is happening, we are vacuuming this relation (think
>>> locks).
>>>
>>> But I am also not going to dig in my heals. If that is truly what -hackers
>>> come up with, thank you at least considering what I said.
>>>
>>> Sincerely,
>>>
>>> JD
>>>
>>
>> As Joshua mentioned, FORCE word might imply doing VACUUM while plowing
>> through locks.
>> I guess that it might confuse the users.
>> IMO, since this option will be a way for emergency, SCANALL word works for me.
>>
>> Or other ideas are,
>> VACUUM IGNOREVM
>> VACUUM RESCURE
>>
>
> Oops, VACUUM RESCUE is correct.
>

Attached draft patch adds SCANALL option to VACUUM in order to scan
all pages forcibly while ignoring visibility map information.
The option name is SCANALL for now but we could change it after got consensus.

Regards,

--
Masahiko Sawada