[postgis-devel] 1.3.3

[Ben Jubb]

Howdy,
In my testing, I did see a performance hit when using the memcmp test, 
although it was noticable only in the largest of my test geometries 
(5000 vertices or so).
The three parameter form seemed like the best way to go because the 
whole point of the prepared version of the functions was to get the best 
possible performance.  The cases when the performance matters most is 
with large geoms, and then the cost of doing the memcmp is the highest.  
Using a third argument seemed the simplest way to get the best possible 
performance from the predicates, with a minimal increase in the 
complexity of the interface.
I agree it would be nice to have a single form for those predicates that 
automatically determines the most efficient manner to do the tests, but 
there didn't seem to be any efficient way to accomplish that. 

b

Paul Ramsey wrote:
> I can comment out the functions in sql.in and the documentation for
> the point release, but as it stands they won't be available to anyone
> who isn't running geos-svn in any event.
>
> I too would rather have the behavior be "automagic" than do the
> three-parameter overload.
>
> Ben, any comments on the performance / implementation aspects?
>
> P
>
> On Fri, Mar 28, 2008 at 1:46 PM, Mark Cave-Ayland
> <mark.cave-ayland at siriusit.co.uk> wrote:
>
>   
>>  Okay. I'm not 100% convinced by the additional 3rd parameter here:
>>  http://postgis.refractions.net/pipermail/postgis-commits/2008-January/000209.html.
>>  I'd like to see evidence that avoiding the memcmp() will actually result
>>  in a more than negligible performance boost, since it seems quite a hack
>>  on the API :(  It would make sense to do this before we release the next
>>  version and people start using the new API in earnest.
>>     
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