Re: pg_stat_progress_basebackup - progress reporting for pg_basebackup, in the server side

On 2020/03/09 14:21, Magnus Hagander wrote:
> On Sun, Mar 8, 2020 at 10:13 PM Kyotaro Horiguchi
> <horikyota(dot)ntt(at)gmail(dot)com> wrote:
>>
>> At Fri, 6 Mar 2020 09:54:09 -0800, Magnus Hagander <magnus(at)hagander(dot)net> wrote in
>>> On Fri, Mar 6, 2020 at 1:51 AM Fujii Masao <masao(dot)fujii(at)oss(dot)nttdata(dot)com> wrote:
>>>> I believe that the time required to estimate the backup size is not so large
>>>> in most cases, so in the above idea, most users don't need to specify more
>>>> option for the estimation. This is good for UI perspective.
>>>>
>>>> OTOH, users who are worried about the estimation time can use
>>>> --no-estimate-backup-size option and skip the time-consuming estimation.
>>>
>>> Personally, I think this is the best idea. it brings a "reasonable
>>> default", since most people are not going to have this problem, and
>>> yet a good way to get out from the issue for those that potentially
>>> have it. Especially since we are now already showing the state that
>>> "walsender is estimating the size", it should be easy enugh for people
>>> to determine if they need to use this flag or not.
>>>
>>> In nitpicking mode, I'd just call the flag --no-estimate-size -- it's
>>> pretty clear things are about backups when you call pg_basebackup, and
>>> it keeps the option a bit more reasonable in length.

+1

>> I agree to the negative option and the shortened name. What if both
>> --no-estimate-size and -P are specifed? Rejecting as conflicting
>> options or -P supercedes? I would choose the former because we don't
>> know which of them has priority.
>
> I would definitely prefer rejecting an invalid combination of options.

+1

So, I will make the patch adding support for --no-estimate-size option
in pg_basebackup.

Regards,

--
Fujii Masao
NTT DATA CORPORATION
Advanced Platform Technology Group
Research and Development Headquarters