Robert Haas <robertmh...@gmail.com> writes: > The release notes say: > <listitem> > <!-- > Author: Tom Lane <t...@sss.pgh.pa.us> > 2018-12-30 [b5415e3c2] Support parameterized TidPaths. > Author: Tom Lane <t...@sss.pgh.pa.us> > 2018-12-30 [0a6ea4001] Add a hash opclass for type "tid". > -->
> <para> > Improve optimization of self-joins (Tom Lane) > </para> > </listitem> > I don't think that's an accurate summary of those two items. It's > true that they could make self-joins more efficient, but my reading is > that it would only do so if the self-join happened to use the ctid > column. Yeah. I think Bruce misread the commit messages, which commented that joining on TID is only likely to be useful in a self-join. > So I think that this should probably be changed to say something like > "Improve optimization of self-joins on ctid columns" or "Improve > optimization of joins involving columns of type tid." The latter seems fine to me. regards, tom lane