Re: KNNGiST for knn-search (WIP)

Robert,

On Wed, 30 Dec 2009, Robert Haas wrote:

> Based on the feedback provided on this patch so far, it looks like
> some changes are probably needed, but it's not entirely clear whether
> the feedback provided is sufficient to provide guidance on what
> changes should be made. It does also need to be updated to CVS HEAD,
> as it no longer applies cleanly.

this is not a problem.

>
> I tend to feel that we should probably target this for 8.6 rather than
> 8.5. We are down to the last CommitFest, and while we don't have a
> nailed-down criterion for what is "too big" for the last CommitFest of
> a given release cycle, this is definitely a big, invasive patch. This
> patch weights in at over 2400 adds/removes, and it's not boilerplate
> stuff like updates to pg_proc entries, but real, significant changes.
> I'm worried that applying something like this late in the release
> cycle is just not a good idea, especially given the fact that it
> probably still needs significant revising. However, I'm fairly
> conservative by nature, so perhaps someone else will have a different
> opinion, or maybe there is a way to restructure it so that the needed
> changes are less invasive.

the patch adds new strategy of gist tree traverse and doesn't change old one,
so there is no risk to ruin old code. I'm all for good conservatism, but
this is not the case, else we wouldn't have GiST at all. We are very
interested in the KNN to be in the 8.5 and we're ready to fix any issues.

From metodological point of view I don't quite understand how to measure
the value of development, I mean what'is a "big patch", "invasive patch".
Should we prefer cosmetic pathces, spelling fixes, etc ? Of course, they are
easy for refering, but people are waiting from us not just fixes, but new
features. For example, KNN-GiST is a big improvement for PostGIS community,
which is a big part of postgres users. Actually, it's PostGIS community, which
supported our work. Now, what we should say them ? The patch was too big and
invasive, so, sorry, wait one year more ? I think it's not good.

Robert, I'm not against you, it's your right to have your opinion. I address
this to other developers. It's important for us, since we have several
other patches ready, for example, long awaited phrase search
(http://www.sai.msu.su/~megera/wiki/2009-08-12) We postponed it, since
it was supposed that EDB will support it, but, hey, it wont. We did it for our
own. Teodor insist to submit it for 8.5, but I'm now begin to hesitate, what if
this patch will be also too big.

Regards,
Oleg
_____________________________________________________________
Oleg Bartunov, Research Scientist, Head of AstroNet (www.astronet.ru)
Sternberg Astronomical Institute, Moscow University, Russia
Internet: oleg(at)sai(dot)msu(dot)su, http://www.sai.msu.su/~megera/
phone: +007(495)939-16-83, +007(495)939-23-83