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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D">Actually the timing test was done on the same machine using PGAdmin-III. What is interesting is that if I return the geometry using something like ST_Simplify(the_geom,
0.1, false) then it returns in just a few hundred milliseconds.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D">David<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>
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<p class="MsoNormal"><b><span style="font-size:11.0pt;font-family:"Calibri",sans-serif">From:</span></b><span style="font-size:11.0pt;font-family:"Calibri",sans-serif"> postgis-users [mailto:postgis-users-bounces@lists.osgeo.org]
<b>On Behalf Of </b>Nordgren, Bryce L -FS<br>
<b>Sent:</b> Friday, March 18, 2016 8:59 AM<br>
<b>To:</b> PostGIS Users Discussion <postgis-users@lists.osgeo.org><br>
<b>Subject:</b> Re: [postgis-users] Slow performance when selecting a geometry column<o:p></o:p></span></p>
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<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D">What kind of network separates client and server? Conservatively assuming that each point is only two 64-bit binary floats, your 560000 points equals 9MB of additional
payload.<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"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D">If you did something like “ST_AsText(geom)”, the additional payload is much, MUCH larger.
<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"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D">I’d also be interested to know if there’s some kind of data manipulation/packing/compression going on between client and server.
<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"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D">Bryce<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>
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<p class="MsoNormal"><b><span style="font-size:11.0pt;font-family:"Calibri",sans-serif">From:</span></b><span style="font-size:11.0pt;font-family:"Calibri",sans-serif"> postgis-users [<a href="mailto:postgis-users-bounces@lists.osgeo.org">mailto:postgis-users-bounces@lists.osgeo.org</a>]
<b>On Behalf Of </b>David Robison<br>
<b>Sent:</b> Friday, March 18, 2016 6:14 AM<br>
<b>To:</b> PostGIS Users Discussion <<a href="mailto:postgis-users@lists.osgeo.org">postgis-users@lists.osgeo.org</a>><br>
<b>Subject:</b> Re: [postgis-users] Slow performance when selecting a geometry column<o:p></o:p></span></p>
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<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D">So there is a total of over 560,000 points in the 8000 records returned. I would have assumed that it was simply returning the contents of the geometry column
and that the number of points (albeit they take up space) would not affect the select time. Is PostGIS doing something with the geometries as it is fetching them from the DB other than just returning them? Thanks, David<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:11.0pt;font-family:"Calibri",sans-serif">From:</span></b><span style="font-size:11.0pt;font-family:"Calibri",sans-serif"> postgis-users [<a href="mailto:postgis-users-bounces@lists.osgeo.org">mailto:postgis-users-bounces@lists.osgeo.org</a>]
<b>On Behalf Of </b>Paul Ramsey<br>
<b>Sent:</b> Thursday, March 17, 2016 9:53 PM<br>
<b>To:</b> PostGIS Users Discussion <<a href="mailto:postgis-users@lists.osgeo.org">postgis-users@lists.osgeo.org</a>><br>
<b>Subject:</b> Re: [postgis-users] Slow performance when selecting a geometry column<o:p></o:p></span></p>
<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">SELECT Sum(ST_NPoints(geom)) FROM thetable;<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">On Thu, Mar 17, 2016 at 5:57 PM, David Robison <<a href="mailto:David.Robison@q-free.com" target="_blank">David.Robison@q-free.com</a>> wrote:<o:p></o:p></p>
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<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto">I am having an issue with a postgis database with the time it takes to query the geometry column. The query selects 8000 records. The time to retrieve the records when not returning
the geometry column is about 100ms. However, the time for the same query when requesting the geometry column takes about 9 seconds. Any thoughts on how I can improve the performance reading the geometry column from a postgis database? I am using PostgreSQL
9.4 and Postgis 22.1.<o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto">Thanks, David
<o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"> <o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;margin-bottom:2.0pt"><b><span style="font-family:"Arial",sans-serif;color:#EE3524">David Robison</span></b><o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;margin-bottom:2.0pt"><i><span style="font-size:10.0pt;font-family:"Arial",sans-serif;color:black">Principal System Engineer</span></i><o:p></o:p></p>
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<a href="tel:%2B1%20757%20546%203401" target="_blank">+1 757 546 3401</a></span><o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;margin-bottom:2.0pt"><span lang="EN-GB" style="font-size:10.0pt;font-family:"Arial",sans-serif;color:black">M.
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<p class="MsoNormal" style="mso-margin-top-alt:auto;margin-bottom:2.0pt"><span style="font-size:10.0pt;font-family:"Arial",sans-serif"><a href="mailto:david.robison@q-free.com" target="_blank">david.robison@q-free.com</a><span style="color:black">
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