On Sun, Apr 13, 2014 at 2:23 PM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
> * I also left out the table documenting which aggregates have this
> optimization. That's not the kind of thing we ordinarily document,
> and it seems inevitable to me that such a table would be noteworthy
> mostly for wrong/incomplete/obsolete information in the future.
I tend to think that not documenting such things is an error. Sure,
the documentation could become obsolete, but I don't see why it's
particularly more likely with this table than anywhere else, and if it
does happen, and people care, they'll submit patches to fix it. More
to the point, when we don't document things like this, it doesn't
cause the knowledge not to be important to end-users; it just means
that the knowledge lives on wiki pages, support fora, and the minds of
people who are "in the know" rather than being easily and generally
accessible. I'd rather have documentation on this topic that was,
say, 80% correct than have none at all.
--
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company