On Sat, 11 Jun 2011, David Fetter wrote:
> On Thu, Jun 09, 2011 at 02:46:54PM -0700, Josh Berkus wrote:
>> All,
>>
>> At pgCon, Tim Child pointed out that Informix had some kind of
>> indexed "near()" function back in 1999. Does anyone know how this
>> was implemented? Is it acutually the first implementation of KNN?
>
> The document below talks about functions for doing this:
>
> http://publib.boulder.ibm.com/infocenter/idshelp/v115/index.jsp?topic=/com.ibm.spatial.doc/sii-funcs-86146.htm
It'd be nice to know how knn was implemented. I'm a bit surprised their
implementation is about spatial objects, while datablade, which is a GiST,
can support different types of objects. So, I'm thinking if Informix did
special implementation of R-tree.
>
>> And if so, does DB2 have it now?
>
> Unsure. I did a quick search and only found Informix references for
> it. They're using R-Trees, so our method, which doesn't, could be a
> differentiator.
>
> Cheers,
> David.
>
Regards,
Oleg
_____________________________________________________________
Oleg Bartunov, Research Scientist, Head of AstroNet (www.astronet.ru),
Sternberg Astronomical Institute, Moscow University, Russia
Internet: oleg@sai.msu.su, http://www.sai.msu.su/~megera/
phone: +007(495)939-16-83, +007(495)939-23-83
