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</o:shapelayout></xml><![endif]--></head><body lang=EN-US link=blue vlink=purple><div class=WordSection1><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Superb.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>That’s clear to me.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Thanks again,<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>V<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>From:</span></b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'> postgis-users-bounces@postgis.refractions.net [mailto:postgis-users-bounces@postgis.refractions.net] <b>On Behalf Of </b>Bryce L Nordgren<br><b>Sent:</b> Thursday, August 11, 2011 2:16 PM<br><b>To:</b> PostGIS Users Discussion<br><b>Subject:</b> Re: [postgis-users] spatial indices on two geometry or rast columns<o:p></o:p></span></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal><br><br><tt><span style='font-size:10.0pt'><a href="mailto:postgis-users-bounces@postgis.refractions.net">postgis-users-bounces@postgis.refractions.net</a> wrote on 08/11/2011 08:56:44 PM:</span></tt><span style='font-size:10.0pt;font-family:"Courier New"'><br><br><tt>> I am not planning to cearch using utm coordinates. The main reason I</tt><br><tt>> would create a utm geom, was so that I could calculate areas, </tt><br><tt>> distances in sq km easily without having to include nested </tt><br><tt>> ST_TRANSFORM statements. In this case would it be useful to have </tt><br><tt>> another index on the utm?</tt></span> <br><br><tt><span style='font-size:10.0pt'>I'd say that a good rule of thumb would be: </span></tt><br><br><tt><span style='font-size:10.0pt'>If the WHERE clause of your SELECT statement names a geometry column, make an index on that column. If the column isn't in the WHERE clause, don't bother. :) </span></tt><br><br><tt><span style='font-size:10.0pt'>Bryce</span></tt><o:p></o:p></p></div></body></html>