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Thread: KNN-GiST and Informix

KNN-GiST and Informix

From
Josh Berkus
Date:
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?

And if so, does DB2 have it now?

--
Josh Berkus
PostgreSQL Experts Inc.
http://pgexperts.com

Re: KNN-GiST and Informix

From
David Fetter
Date:
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

> 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.
--
David Fetter <david@fetter.org> http://fetter.org/
Phone: +1 415 235 3778  AIM: dfetter666  Yahoo!: dfetter
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Re: KNN-GiST and Informix

From
Oleg Bartunov
Date:
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