Hi Fuiji, I wasn't aware that support for exporting snapshots goes as far back as v10. The change looks good.
Thanks, Kevin On Fri, May 23, 2025 at 7:12 AM Fujii Masao <masao.fu...@oss.nttdata.com> wrote: > > > On 2025/05/22 20:53, PG Doc comments form wrote: > > The following documentation comment has been logged on the website: > > > > Page: > https://www.postgresql.org/docs/17/logicaldecoding-explanation.html > > Description: > > > > Hi, > > I'm referring to this bit at the very end of the page: Creation of a > > snapshot is not always possible. In particular, it will fail when > connected > > to a hot standby. Applications that do not require snapshot export may > > suppress it with the NOEXPORT_SNAPSHOT option. > > It's not clear what the intention of this is (is it referring only to > > physical replication slots?) but as it stands you can export snapshots > while > > creating a logical replication slot. This should have been possible > starting > > PG16, I've tested this on PG17. > > The description "Creation of a snapshot is not always possible. In > particular, > it will fail when connected to a hot standby." no longer seems accurate. > Since v10 (commit 6c2003f8a1b), exporting snapshots on a standby has been > supported. > > This description was accurate when the first patch [1] adding that > description > was written, but I think we just overlooked updating it later. > > > > As an aside, I think NOEXPORT_SNAPSHOT is from the older syntax of > > CREATE_REPLICATION_SLOT and should be swapped with SNAPSHOT 'nothing'. > > Yes, so how about the following change? > > <para> > - Creation of a snapshot is not always possible. In particular, it > will > - fail when connected to a hot standby. Applications that do not > require > - snapshot export may suppress it with the > <literal>NOEXPORT_SNAPSHOT</literal> > + Applications that do not require > + snapshot export may suppress it with the <literal>SNAPSHOT > 'nothing'</literal> > option. > </para> > > Regards, > > [1] > https://www.postgresql.org/message-id/CAMsr+YFjxv0T8Yi1Q=3tvdgviu2bm+fb_-xubtfxhsnldns...@mail.gmail.com > > Regards, > > -- > Fujii Masao > Advanced Computing Technology Center > Research and Development Headquarters > NTT DATA CORPORATION > >
