<html xmlns:v="urn:schemas-microsoft-com:vml" xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns:m="http://schemas.microsoft.com/office/2004/12/omml" xmlns="http://www.w3.org/TR/REC-html40">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=us-ascii">
<meta name="Generator" content="Microsoft Word 12 (filtered medium)">
<style>
<!--
/* Font Definitions */
@font-face
{font-family:Calibri;
panose-1:2 15 5 2 2 2 4 3 2 4;}
@font-face
{font-family:Tahoma;
panose-1:2 11 6 4 3 5 4 4 2 4;}
@font-face
{font-family:Consolas;
panose-1:2 11 6 9 2 2 4 3 2 4;}
@font-face
{font-family:"Times New Roman \, serif";
panose-1:0 0 0 0 0 0 0 0 0 0;}
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
{margin:0in;
margin-bottom:.0001pt;
font-size:11.0pt;
font-family:"Calibri","sans-serif";
color:black;}
a:link, span.MsoHyperlink
{mso-style-priority:99;
color:blue;
text-decoration:underline;}
a:visited, span.MsoHyperlinkFollowed
{mso-style-priority:99;
color:purple;
text-decoration:underline;}
p
{mso-style-priority:99;
mso-margin-top-alt:auto;
margin-right:0in;
mso-margin-bottom-alt:auto;
margin-left:0in;
font-size:12.0pt;
font-family:"Times New Roman","serif";
color:black;}
pre
{mso-style-priority:99;
mso-style-link:"HTML Preformatted Char";
margin:0in;
margin-bottom:.0001pt;
font-size:10.0pt;
font-family:"Courier New";
color:black;}
span.HTMLPreformattedChar
{mso-style-name:"HTML Preformatted Char";
mso-style-priority:99;
mso-style-link:"HTML Preformatted";
font-family:Consolas;
color:black;}
span.EmailStyle20
{mso-style-type:personal;
font-family:"Calibri","sans-serif";
color:windowtext;}
span.EmailStyle21
{mso-style-type:personal;
font-family:"Calibri","sans-serif";
color:#1F497D;}
span.EmailStyle22
{mso-style-type:personal-reply;
font-family:"Calibri","sans-serif";
color:#1F497D;}
.MsoChpDefault
{mso-style-type:export-only;
font-size:10.0pt;}
@page Section1
{size:8.5in 11.0in;
margin:1.0in 1.0in 1.0in 1.0in;}
div.Section1
{page:Section1;}
-->
</style><!--[if gte mso 9]><xml>
<o:shapedefaults v:ext="edit" spidmax="1026" />
</xml><![endif]--><!--[if gte mso 9]><xml>
<o:shapelayout v:ext="edit">
<o:idmap v:ext="edit" data="1" />
</o:shapelayout></xml><![endif]-->
</head>
<body bgcolor="white" lang="EN-US" link="blue" vlink="purple">
<div class="Section1">
<p class="MsoNormal"><span style="color:#1F497D">Hi Birgit,<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D">I also don’t know whether st_union is using spatial_index because new to postgis.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"> <o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D">I am having GUI which shows the data over map.
<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D">Suppose user will make query on table1 and queried data display on map. Queried data is geometry type data.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D">Again user will make query on table2 and queried data display on map. Queried data is also geometry type data<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D">Again user will make query on table3 and queried data display on map. Queried data is also geometry type data<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D">At the end I want to union above three queried data and display on map using resultant queried union data.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D">Please suggest me is there other way to union geometry data.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D">Thanks<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D">Atul <o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"><o:p> </o:p></span></p>
<div>
<div style="border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0in 0in 0in">
<p class="MsoNormal"><b><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif";
color:windowtext">From:</span></b><span style="font-size:10.0pt;font-family:
"Tahoma","sans-serif";color:windowtext"> postgis-users-bounces@postgis.refractions.net [mailto:postgis-users-bounces@postgis.refractions.net]
<b>On Behalf Of </b>Birgit Laggner<br>
<b>Sent:</b> Thursday, November 24, 2011 2:42 PM<br>
<b>To:</b> postgis-users@postgis.refractions.net<br>
<b>Subject:</b> Re: [postgis-users] Help me.<o:p></o:p></span></p>
</div>
</div>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Hi Atul,<br>
<br>
are you really sure, you want to union all geometries of the three tables into one big multipolygon? It seems to me that this might be a little bit too complex and big...
<br>
<br>
But, if you really want to union all these geometries (and I am not sure, if this would really be your plan - because maybe you are mistaken that union in PostGIS means the same as in ArcGIS??), then I would split the query again to first do the union of the
first two tables, while immediately dumping the resulting multipolygon into the consisting single polygons, and next, I would go for the union with the third table. The queries could look like this:<br>
<br>
select (st_dump(st_union(t1.geometry, t2.geometry))).geom as geometry into new_table from TEMP_OUTPUTTREE_2 t1, TEMP_OUTPUTTREE2_4 t2;<br>
<br>
select (st_dump(st_union(nt.geometry, t3.geometry))).geom as geometry from new_table nt, TEMP_OUTPUTTREE_5 t3;<br>
<br>
I don't know if st_union is using the spatial index. If the answer would be yes, it might be useful to create one on the new_table. But, depending on the size of your tables, I am afraid, that the queries will still be much slower than your intersection-queries.<br>
<br>
Good luck and regards,<br>
<br>
Birgit.<br>
<br>
<br>
<br>
Am 24.11.2011 07:37, schrieb Atul Kumar: <o:p></o:p></p>
<p class="MsoNormal"><span style="color:#1F497D">Hi Birgit,</span><o:p></o:p></p>
<p class="MsoNormal"><span style="color:#1F497D"> </span><o:p></o:p></p>
<p class="MsoNormal"><span style="color:#1F497D">Now its taking less time as compare to previous one.</span><o:p></o:p></p>
<p class="MsoNormal"><span style="color:#1F497D"> </span><o:p></o:p></p>
<p class="MsoNormal"><span style="color:#1F497D">One more help. </span><o:p></o:p></p>
<p class="MsoNormal"><span style="color:#1F497D"> </span><o:p></o:p></p>
<p class="MsoNormal"><span style="color:#1F497D">Is there any way to optimize this query because its also taking long time to execute.</span><o:p></o:p></p>
<p class="MsoNormal"><span style="color:#1F497D"> </span><o:p></o:p></p>
<p class="MsoNormal"><span style="color:#1F497D">select st_union (st_union (t1.geometry, t2.geometry), t3.geometry) geometry from TEMP_OUTPUTTREE_2 t1,TEMP_OUTPUTTREE2_4 t2, TEMP_OUTPUTTREE_5 t3</span><o:p></o:p></p>
<p class="MsoNormal"> <o:p></o:p></p>
<p class="MsoNormal"><span style="color:#1F497D">Thanks</span><o:p></o:p></p>
<p class="MsoNormal"><span style="color:#1F497D">Atul</span><o:p></o:p></p>
<p class="MsoNormal"><span style="color:#1F497D"> </span><o:p></o:p></p>
<p class="MsoNormal"><span style="color:#1F497D"> </span><o:p></o:p></p>
<div>
<div style="border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0in 0in 0in">
<p class="MsoNormal"><b><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif";
color:windowtext">From:</span></b><span style="font-size:10.0pt;font-family:
"Tahoma","sans-serif";color:windowtext">
<a href="mailto:postgis-users-bounces@postgis.refractions.net">postgis-users-bounces@postgis.refractions.net</a> [<a href="mailto:postgis-users-bounces@postgis.refractions.net">mailto:postgis-users-bounces@postgis.refractions.net</a>]
<b>On Behalf Of </b>Birgit Laggner<br>
<b>Sent:</b> Wednesday, November 23, 2011 6:07 PM<br>
<b>To:</b> <a href="mailto:postgis-users@postgis.refractions.net">postgis-users@postgis.refractions.net</a><br>
<b>Subject:</b> Re: [postgis-users] Help me.</span><o:p></o:p></p>
</div>
</div>
<p class="MsoNormal"> <o:p></o:p></p>
<p class="MsoNormal">Hallo Atul,<br>
<br>
perhaps, I would split the query in two queries, because otherwise I think it might be difficult to use a spatial index on the second intersection. The queries could be like this:<br>
<br>
--create a spatial index on each input table:<br>
create index temp_outputtree_2_gist_geometry on temp_outputtree_2 using gist(geometry);<br>
create index temp_outputtree2_4_gist_geometry on temp_outputtree2_4 using gist(geometry);<br>
create index temp_outputtree_5_gist_geometry on temp_outputtree_5 using gist(geometry);<br>
<br>
--intersection of the first 2 tables using the spatial index, writing the result of it into a new table:<br>
select st_intersection(t1.geometry,t2.geometry) as geometry into new_table from TEMP_OUTPUTTREE_2 t1 inner join TEMP_OUTPUTTREE2_4 t2 on t1.geometry && t2.geometry where st_intersects(t1.geometry,t2.geometry);<br>
<br>
--create a spatial index on the new geometries of the first intersection:<br>
create index new_table_gist_geometry on new_table using gist(geometry);<br>
<br>
--intersection with the third table:<br>
select st_intersection(nt.geometry,t3.geometry) as geometry from new_table nt inner join TEMP_OUTPUTTREE_5 t3 on nt.geometry && t3.geometry where st_intersects(nt.geometry,t3.geometry);<br>
<br>
Hope that helps,<br>
<br>
Birgit.<br>
<br>
Am 23.11.2011 13:16, schrieb Atul Kumar: <o:p></o:p></p>
<p class="MsoNormal">Hi All,<o:p></o:p></p>
<p class="MsoNormal"> <o:p></o:p></p>
<p class="MsoNormal">I am trying to intersection multiple sets of geographical data using ST_intersection function. But query execution time is long.
<o:p></o:p></p>
<p class="MsoNormal">My Query is : <o:p></o:p></p>
<p class="MsoNormal">select st_intersection (st_intersection (t1.geometry, t2.geometry), t3.geometry) geometry from TEMP_OUTPUTTREE_2 t1,TEMP_OUTPUTTREE2_4 t2, TEMP_OUTPUTTREE_5 t3<o:p></o:p></p>
<p class="MsoNormal"> <o:p></o:p></p>
<p class="MsoNormal">I am having three table its having geometry data. I want to intersect operation on those data.<o:p></o:p></p>
<p class="MsoNormal"> <o:p></o:p></p>
<p class="MsoNormal">Please suggest, Is there any optimal way to get the intersection with less execution time?<o:p></o:p></p>
<p class="MsoNormal"> <o:p></o:p></p>
<p class="MsoNormal">Thanks<o:p></o:p></p>
<p class="MsoNormal">Atul Kumar<o:p></o:p></p>
<p class="MsoNormal"> <o:p></o:p></p>
<p>DISCLAIMER ========== This e-mail may contain privileged and confidential information which is the property of Persistent Systems Ltd. It is intended only for the use of the individual or entity to which it is addressed. If you are not the intended recipient,
you are not authorized to read, retain, copy, print, distribute or use this message. If you have received this communication in error, please notify the sender and delete all copies of this message. Persistent Systems Ltd. does not accept any liability for
virus infected mails.<o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Times New Roman , serif","serif""><br>
<br>
<br>
<br>
</span><o:p></o:p></p>
<pre>_______________________________________________<o:p></o:p></pre>
<pre>postgis-users mailing list<o:p></o:p></pre>
<pre><a href="mailto:postgis-users@postgis.refractions.net">postgis-users@postgis.refractions.net</a><o:p></o:p></pre>
<pre><a href="http://postgis.refractions.net/mailman/listinfo/postgis-users">http://postgis.refractions.net/mailman/listinfo/postgis-users</a><o:p></o:p></pre>
<p>DISCLAIMER ========== This e-mail may contain privileged and confidential information which is the property of Persistent Systems Ltd. It is intended only for the use of the individual or entity to which it is addressed. If you are not the intended recipient,
you are not authorized to read, retain, copy, print, distribute or use this message. If you have received this communication in error, please notify the sender and delete all copies of this message. Persistent Systems Ltd. does not accept any liability for
virus infected mails.<o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Times New Roman","serif""><br>
<br>
<br>
<o:p></o:p></span></p>
<pre>_______________________________________________<o:p></o:p></pre>
<pre>postgis-users mailing list<o:p></o:p></pre>
<pre><a href="mailto:postgis-users@postgis.refractions.net">postgis-users@postgis.refractions.net</a><o:p></o:p></pre>
<pre><a href="http://postgis.refractions.net/mailman/listinfo/postgis-users">http://postgis.refractions.net/mailman/listinfo/postgis-users</a><o:p></o:p></pre>
</div>
<p>DISCLAIMER
==========
This e-mail may contain privileged and confidential information which is the property of Persistent Systems Ltd. It is intended only for the use of the individual or entity to which it is addressed. If you are not the intended recipient, you are not authorized to read, retain, copy, print, distribute or use this message. If you have received this communication in error, please notify the sender and delete all copies of this message. Persistent Systems Ltd. does not accept any liability for virus infected mails.</p>
</body>
</html>