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Re: KNN-GiST and Informix

From: Oleg Bartunov <oleg(at)sai(dot)msu(dot)su>
To: David Fetter <david(at)fetter(dot)org>
Cc: Josh Berkus <josh(at)agliodbs(dot)com>, pgsql-advocacy(at)postgresql(dot)org
Subject: Re: KNN-GiST and Informix
Date: 2011-06-11 18:17:23
Message-ID: Pine.LNX.4.64.1106112214230.9772@sn.sai.msu.ru (view raw or flat)
Thread:
Lists: pgsql-advocacy
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(at)sai(dot)msu(dot)su, http://www.sai.msu.su/~megera/
phone: +007(495)939-16-83, +007(495)939-23-83

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