On Wed, 20 Jan 2021 at 03:47, Stephen Frost <sfr...@snowman.net> wrote: > Greetings, > > * Tom Lane (t...@sss.pgh.pa.us) wrote: >> Stephen Frost <sfr...@snowman.net> writes: >> > Any further comments or thoughts on this one? >> >> This: >> >> + total time between checkpoints. The default is 0.9, which spreads >> the >> + checkpoint across the entire checkpoint timeout period of time, >> >> is confusing because 0.9 is obviously not 1.0; people will wonder >> whether the scale is something strange or the text is just wrong. >> They will also wonder why not use 1.0 instead. So perhaps more like >> >> ... The default is 0.9, which spreads the checkpoint across almost >> all the available interval, providing fairly consistent I/O load >> while also leaving some slop for checkpoint completion overhead. >> >> The other chunk of text seems accurate, but there's no reason to let >> this one be misleading. > > Good point, updated along those lines. > > In passing, I noticed that we have a lot of documentation like: > > This parameter can only be set in the postgresql.conf file or on the > server command line. > > ... which hasn't been true since the introduction of ALTER SYSTEM. I > don't really think it's this patch's job to clean that up but it doesn't > seem quite right that we don't include ALTER SYSTEM in that list either. > If this was C code, maybe we could get away with just changing such > references as we find them, but I don't think we'd want the > documentation to be in an inconsistent state regarding that. >
I have already mentioned this in [1], however it seems unattractive. [1] - https://www.postgresql.org/message-id/flat/199703E4-A795-4FB8-911C-D0DE9F51519C%40hotmail.com -- Regrads, Japin Li. ChengDu WenWu Information Technology Co.,Ltd.
