Hi út 28. 12. 2021 v 9:28 odesílatel Sascha Kuhl <yogidaba...@gmail.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? > Fujii Masao <masao.fu...@oss.nttdata.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 >> >> >>
