Sorry for the late reply.
On Wed, 06 Jul 2022 at 08:02, Tom Lane <t...@sss.pgh.pa.us> wrote: > Japin Li <japi...@hotmail.com> writes: >> [ v4-wal-level-documentation.patch ] > > Hm, I don't care for the wording here: > > + A precondition for using minimal WAL is to disable WAL archiving and > + streaming replication by setting <varname>archive_mode</varname> to > + <literal>off</literal>, and <xref linkend="guc-max-wal-senders"/> to > + <literal>0</literal>. > > "Precondition" is an overly fancy word that makes things less clear > not more so. Does it mean that setting wal_level = minimal will fail > if you don't do these other things, or does it just mean that you > won't be getting the absolute minimum WAL volume? If the former, > I think it'd be better to say something like "To set wal_level to minimal, > you must also set [these variables], which has the effect of disabling > both WAL archiving and streaming replication." Yeah, it's the former case. > > + servers. If setting <varname>max_wal_senders</varname> to > + <literal>0</literal> consider also reducing the amount of WAL > produced > + by changing <varname>wal_level</varname> to > <literal>minimal</literal>. > > I don't think this is great advice. It will encourage people to use > wal_level = minimal even if they have other requirements that weigh > against it. If they feel that their system is producing too much > WAL, I doubt they'll have a hard time finding the wal_level knob. > Agreed. It isn't good advice. We can remove the suggestion. -- Regrads, Japin Li. ChengDu WenWu Information Technology Co.,Ltd.
