[postgis-tickets] [PostGIS] #3065: Spatial index on LINESTRING not used under some circumstances

[PostGIS]

#3065: Spatial index on LINESTRING not used under some circumstances
---------------------------+------------------------------------------------
 Reporter:  realityexists  |       Owner:  pramsey      
     Type:  defect         |      Status:  new          
 Priority:  medium         |   Milestone:  PostGIS 2.1.6
Component:  postgis        |     Version:  2.1.x        
 Keywords:                 |  
---------------------------+------------------------------------------------
Changes (by robe):

  * milestone:  => PostGIS 2.1.6


Comment:

 Okay I started with a spanking new install which should replicate yours,
 and still it does an index scan as I would expect even in a transaction


 {{{
 POSTGIS="2.1.5 r13152" GEOS="3.4.2-CAPI-1.8.2 r3924" PROJ="Rel. 4.8.0, 6
 March 2012" GDAL="GDAL 1.11.1, released 2014/09/24" LIBXML="2.7.8"
 LIBJSON="UNKNOWN" RASTER PostgreSQL 9.3.6, compiled by Visual C++ build
 1600, 64-bit
 }}}



 {{{
 Nested Loop  (cost=0.14..585.98 rows=328 width=8)
   ->  Seq Scan on test_poly a  (cost=0.00..22.30 rows=1230 width=36)
   ->  Index Scan using ix__temp_line_line on _temp_line s
 (cost=0.14..0.45 rows=1 width=36)
         Index Cond: (a.border && line)
         Filter: (_st_distance(a.border, line, 0::double precision, false)
 < 1e-005::double precision)

 }}}

 Not sure how you are getting a materialized step. I was running with
 factory settings
 so perhaps it's sensitive to your settings.

 here is my show stuff


 {{{
 show work_mem; -- 1MB
 show shared_buffers; -- 128MB

 }}}

-- 
Ticket URL: <http://trac.osgeo.org/postgis/ticket/3065#comment:11>
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