Re: sequences vs. synchronous replication

út 28. 12. 2021 v 9:53 odesílatel Sascha Kuhl <yogidabanli(at)gmail(dot)com>
napsal:

>
>
> Pavel Stehule <pavel(dot)stehule(at)gmail(dot)com> schrieb am Di., 28. Dez. 2021,
> 09:51:
>
>> Hi
>>
>> út 28. 12. 2021 v 9:28 odesílatel Sascha Kuhl <yogidabanli(at)gmail(dot)com>
>> napsal:
>>
>>> Sequence validation by step, in total is great. If the sequence is
>>> Familie or professional, does it make sense to a have a total validation by
>>> an expert. I can only say true by chi square Networks, but would a medical
>>> opinion be an improvement?
>>>
>>
>> Is it generated by boot or by a human?
>>
>
> I validation my family and Société, only when them Show me not their
> Sekret, part of their truth. Works fine by a Boot level, as far as I can
> detektei, without the Boot showing up 😉
>

don't spam this mailing list, please

Thank you

Pavel

>>
>>
>>> Fujii Masao <masao(dot)fujii(at)oss(dot)nttdata(dot)com> schrieb am Di., 28. Dez.
>>> 2021, 07:56:
>>>
>>>>
>>>>
>>>> On 2021/12/24 19:40, Tomas Vondra wrote:
>>>> > Maybe, but what would such workload look like? Based on the tests I
>>>> did, such workload probably can't generate any WAL. The amount of WAL added
>>>> by the change is tiny, the regression is caused by having to flush WAL.
>>>> >
>>>> > The only plausible workload I can think of is just calling nextval,
>>>> and the cache pretty much fixes that.
>>>>
>>>> Some users don't want to increase cache setting, do they? Because
>>>>
>>>> - They may expect that setval() affects all subsequent nextval(). But
>>>> if cache is set to greater than one, the value set by setval() doesn't
>>>> affect other backends until they consumed all the cached sequence values.
>>>> - They may expect that the value returned from nextval() is basically
>>>> increased monotonically. If cache is set to greater than one, subsequent
>>>> nextval() can easily return smaller value than one returned by previous
>>>> nextval().
>>>> - They may want to avoid "hole" of a sequence as much as possible,
>>>> e.g., as far as the server is running normally. If cache is set to greater
>>>> than one, such "hole" can happen even thought the server doesn't crash yet.
>>>>
>>>>
>>>> > FWIW I plan to explore the idea of looking at sequence page LSN, and
>>>> flushing up to that position.
>>>>
>>>> Sounds great, thanks!
>>>>
>>>> Regards,
>>>>
>>>> --
>>>> Fujii Masao
>>>> Advanced Computing Technology Center
>>>> Research and Development Headquarters
>>>> NTT DATA CORPORATION
>>>>
>>>>
>>>>