[postgis-devel] [PostGIS] #536: Get rid of the STRICT on geography ST_Intersects

[PostGIS]

#536: Get rid of the STRICT on geography ST_Intersects
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  Reporter:  robe     |       Owner:  pramsey      
      Type:  defect   |      Status:  new          
  Priority:  high     |   Milestone:  PostGIS 1.5.2
 Component:  postgis  |     Version:  1.5.X        
Resolution:           |    Keywords:               
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Comment (by anarazel):

 I read this bug via Reginas Blog and can explain the issue at least a bit.
 There are several conditions causing strict functions to fail:

  * it uses other, non-strict functions. If it would get the strictness
 would get lost. Imageine a unstrict function add(a, b) := coalesce(a, 0) +
 coalesce(b, 0) and strict strict_add(a, b) := add(a,b). If strict_add()
 would get inlined the promise of it returning NULL if any of its
 parameters are NULL does not hold true anymore.

  * some of the parameters are not used at all. Example: strict func_a(a,
 b) := a. If that would get inlined the definition would change.


 Those conditions are *completely* orthogonal to those imposed by
 volatility - which imposes a different set of constraints.

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Ticket URL: <http://trac.osgeo.org/postgis/ticket/536#comment:12>
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