[postgis-devel] ST_Envelope & spatial index
Andrea Peri
aperi2007 at gmail.com
Tue Mar 13 14:47:56 PDT 2012
>>* explain select ST_Extent(ST_Envelope(rast)) from raster.ofc10k_2010 limit 1;*>>* *>>* And see that.*>>* *>>* Limit (cost=48027.93..48027.94 rows=1 width=32)*>>* -> Aggregate (cost=48027.93..48027.94 rows=1 width=32)*>>* -> Seq Scan on ofc10k_2010 (cost=0.00..37419.53 rows=1414453*>>* width=32)*>>*
*>Try this:
>
>SELECT ST_Extent(rast::geometry) from raster.ofc10k_2010;
>
>Pierre
Hi, Pierre,
I test you query (with limit 1 to have same conditions).
SELECT ST_Extent(rast::geometry) from raster.ofc10k_2010 limit 1;
It report this cost:
It is rather the same.
Limit (cost=44491.80..44491.81 rows=1 width=32)
-> Aggregate (cost=44491.80..44491.81 rows=1 width=32)
-> Seq Scan on ofc10k_2010 (cost=0.00..37419.53 rows=1414453
width=32)
--
-----------------
Andrea Peri
. . . . . . . . .
qwerty àèìòù
-----------------
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.osgeo.org/pipermail/postgis-devel/attachments/20120313/65a044f9/attachment.html>
More information about the postgis-devel
mailing list