<html><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8"
data-hsystem="true"></head><body><style>p{margin: 0;padding: 0;}</style><p>this
post has a decent example of the use (and limitation) of the existing KNN
operators</p><p><br></p><p><br></p><p>
http://blog.light42.com/wordpress/?p=102</p><p><br></p><p>--</p><p>Brian M
Hamlin</p><p>OSGeo California
Chapter</p><p>blog.light42.com</p><p><br></p><p><br></p><p><br></p><p>On Fri, 17
Jan 2014 09:04:24 -0500, Paul Ramsey <pramsey@cleverelephant.ca>
wrote:<br></p><blockquote dir="ltr" style="border-left: 2px solid rgb(0, 0, 0);
padding-right: 0px; padding-left: 5px; margin-left: 5px; margin-right: 0px;"
_mce_style="border-left: 2px solid #000000; padding-right: 0px; padding-left:
5px; margin-left: 5px; margin-right: 0px;"><div id="html-message"><style><!--
body{font-family:Helvetica,Arial;font-size:13px}
--></style><style _mce_bogus="1"><!--
body{font-family:Helvetica,Arial;font-size:13px}
--></style><div id="bloop_customfont"
style="font-family:Helvetica,Arial;font-size:13px; color: rgba(0,0,0,1.0);
margin: 0px; line-height: auto;" _mce_style="font-family: Helvetica,Arial;
font-size: 13px; color: rgba(0,0,0,1.0); margin: 0px; line-height:
auto;">Alex,</div><div id="bloop_customfont"
style="font-family:Helvetica,Arial;font-size:13px; color: rgba(0,0,0,1.0);
margin: 0px; line-height: auto;" _mce_style="font-family: Helvetica,Arial;
font-size: 13px; color: rgba(0,0,0,1.0); margin: 0px; line-height:
auto;"><br></div><div id="bloop_customfont"
style="font-family:Helvetica,Arial;font-size:13px; color: rgba(0,0,0,1.0);
margin: 0px; line-height: auto;" _mce_style="font-family: Helvetica,Arial;
font-size: 13px; color: rgba(0,0,0,1.0); margin: 0px; line-height: auto;">This
piece of the workshop gives some visuals about how unpleasant reasoning abound
nearest neighbour using boxes is. (It’s almost embarrassing trying to explain
it to people)</div><div id="bloop_customfont"
style="font-family:Helvetica,Arial;font-size:13px; color: rgba(0,0,0,1.0);
margin: 0px; line-height: auto;" _mce_style="font-family: Helvetica,Arial;
font-size: 13px; color: rgba(0,0,0,1.0); margin: 0px; line-height:
auto;"><br></div><div id="bloop_customfont"
style="font-family:Helvetica,Arial;font-size:13px; color: rgba(0,0,0,1.0);
margin: 0px; line-height: auto;" _mce_style="font-family: Helvetica,Arial;
font-size: 13px; color: rgba(0,0,0,1.0); margin: 0px; line-height:
auto;">http://workshops.boundlessgeo.com/postgis-intro/knn.html</div><div
id="bloop_customfont" style="font-family:Helvetica,Arial;font-size:13px; color:
rgba(0,0,0,1.0); margin: 0px; line-height: auto;" _mce_style="font-family:
Helvetica,Arial; font-size: 13px; color: rgba(0,0,0,1.0); margin: 0px;
line-height: auto;"><br></div><div id="bloop_customfont"
style="font-family:Helvetica,Arial;font-size:13px; color: rgba(0,0,0,1.0);
margin: 0px; line-height: auto;" _mce_style="font-family: Helvetica,Arial;
font-size: 13px; color: rgba(0,0,0,1.0); margin: 0px; line-height: auto;">You
can pull the NYC roads data from the associated data package and replicate the
results. </div><div id="bloop_customfont"
style="font-family:Helvetica,Arial;font-size:13px; color: rgba(0,0,0,1.0);
margin: 0px; line-height: auto;" _mce_style="font-family: Helvetica,Arial;
font-size: 13px; color: rgba(0,0,0,1.0); margin: 0px; line-height: auto;">I can
prepare something more plug-n-play (dump file and SQL examples) when I get back
home if needed.</div><div id="bloop_customfont"
style="font-family:Helvetica,Arial;font-size:13px; color: rgba(0,0,0,1.0);
margin: 0px; line-height: auto;" _mce_style="font-family: Helvetica,Arial;
font-size: 13px; color: rgba(0,0,0,1.0); margin: 0px; line-height:
auto;"><br></div><div id="bloop_customfont"
style="font-family:Helvetica,Arial;font-size:13px; color: rgba(0,0,0,1.0);
margin: 0px; line-height: auto;" _mce_style="font-family: Helvetica,Arial;
font-size: 13px; color: rgba(0,0,0,1.0); margin: 0px; line-height:
auto;">P.</div> <div id="bloop_sign_1389967365621223936"
class="bloop_sign"><div><br></div><span
style="font-family:helvetica,arial;font-size:13px" _mce_style="font-family:
helvetica,arial; font-size: 13px;"></span>-- <br>Paul
Ramsey<br>http://cleverelephant.ca<div>http://postgis.net</div></div> <br><p
style="color:#A0A0A8;" _mce_style="color: #a0a0a8;">On January 17, 2014 at
9:01:33 AM, Alexander Korotkov (<a href="mailto://aekorotkov@gmail.com"
target="">aekorotkov@gmail.com</a>) wrote:</p> <blockquote type="cite"
class="clean_bq"><span><div><div class="gmail_extra" style="color: rgb(0, 0, 0);
font-family: helvetica; font-size: 13px; font-style: normal; font-variant:
normal; font-weight: normal; letter-spacing: normal; line-height: normal;
orphans: auto; text-align: start; text-indent: 0px; text-transform: none;
white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width:
0px;" _mce_style="color: #000000; font-family: helvetica; font-size: 13px;
font-style: normal; font-variant: normal; font-weight: normal; letter-spacing:
normal; line-height: normal; orphans: auto; text-align: start; text-indent: 0px;
text-transform: none; white-space: normal; widows: auto; word-spacing: 0px;"><br
class="Apple-interchange-newline">You may take a look at my patch to PostgreSQL
enabling exact knn-gist:</div><div class="gmail_extra" style="color: rgb(0, 0,
0); font-family: helvetica; font-size: 13px; font-style: normal; font-variant:
normal; font-weight: normal; letter-spacing: normal; line-height: normal;
orphans: auto; text-align: start; text-indent: 0px; text-transform: none;
white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width:
0px;" _mce_style="color: #000000; font-family: helvetica; font-size: 13px;
font-style: normal; font-variant: normal; font-weight: normal; letter-spacing:
normal; line-height: normal; orphans: auto; text-align: start; text-indent: 0px;
text-transform: none; white-space: normal; widows: auto; word-spacing: 0px;"><a
href="http://www.postgresql.org/message-id/CAPpHfdu_qBLNRnv-r=_tofZYYa6-r=Z5_MGF4_phAOkWcYxfRg@mail.gmail.com"
target="">http://www.postgresql.org/message-id/CAPpHfdu_qBLNRnv-r=_tofZYYa6-r=Z5_MGF4_phAOkWcYxfRg@mail.gmail.com</a><br></div><div
class="gmail_extra" style="color: rgb(0, 0, 0); font-family: helvetica;
font-size: 13px; font-style: normal; font-variant: normal; font-weight: normal;
letter-spacing: normal; line-height: normal; orphans: auto; text-align: start;
text-indent: 0px; text-transform: none; white-space: normal; widows: auto;
word-spacing: 0px; -webkit-text-stroke-width: 0px;" _mce_style="color: #000000;
font-family: helvetica; font-size: 13px; font-style: normal; font-variant:
normal; font-weight: normal; letter-spacing: normal; line-height: normal;
orphans: auto; text-align: start; text-indent: 0px; text-transform: none;
white-space: normal; widows: auto; word-spacing: 0px;">Ideally, it could be in
9.4. But I expect serious critics about accessing heap from gist is
fundamentally bad design.</div><div class="gmail_extra" style="color: rgb(0, 0,
0); font-family: helvetica; font-size: 13px; font-style: normal; font-variant:
normal; font-weight: normal; letter-spacing: normal; line-height: normal;
orphans: auto; text-align: start; text-indent: 0px; text-transform: none;
white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width:
0px;" _mce_style="color: #000000; font-family: helvetica; font-size: 13px;
font-style: normal; font-variant: normal; font-weight: normal; letter-spacing:
normal; line-height: normal; orphans: auto; text-align: start; text-indent: 0px;
text-transform: none; white-space: normal; widows: auto; word-spacing:
0px;">Test cases are very welcome. It would be very nice to have them
before<span class="Apple-converted-space"> </span><a
href="http://airmail.calendar/2014-01-19%2012:00:00%20EST" target="">January
19.</a><span class="Apple-converted-space"> </span>I know it very soon, but in
this case I can include them to PGCon proposal.</div><br
class="Apple-interchange-newline"></div></span></blockquote></div>
<br><hr><br>
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