MapServer Oracle - MS or OGR?

[William Kyngesburye]

On Mar 30, 2006, at 9:41 AM, Frank Warmerdam wrote:

> William Kyngesburye wrote:
>> I'm wondering how MapServer's builtin Oracle support is different  
>> from OGR's?  Feature support and performance.
>
> William,
>
> I think the main downside of OGR Oracle support is performance.  Going
> throug the extra "OGRFeature" layer has to cost something.  The other
> issue I think is that the direct access in MapServer allows the user
> to specify a highly customized query but still have MapServer add
> the spatial component to it, so that all the query is done in Oracle.
>
> If you go through OGR you have two choices.  If you use a custom query
> then then OGR is too dumb to know how to add the spatial component  
> into
> it and so (I assume) the spatial query is done in OGR after fetching
> from the DB.  If you just use normal table access with (with perhaps a
> simple WHERE clause in your FILTER) then OGR will pass the spatial  
> query
> into Oracle to resolve.
>
I kinda figured it might be something like that.

>> I would rather use Oracle from GDAL.  My concern is that Oracle  
>> support is fixed into the MapServer binary, either it has it or it  
>> doesn't.  No plugin mechanism in MapServer (or is there?).
>
> In 4.8 there *is* a plugin mechanism but the build architecture has no
> particular support to utilize it to make something like the oracle  
> driver
> a plugin.  So it is practical, but not terribly easy, to make the  
> oracle
> support a plugin for mapserver.
>
Is there any documentation on the hidden plugin mechanism?  All I  
found on the MS site was an RFC to add this feature.

> >  If it does, a user must
>> install the Oracle Instant Client to use MapServer even if they  
>> don't use Oracle (tho there is the weak link trick in Darwin).   
>> But with OGR, one should be able to build Oracle support as a  
>> plugin, much like the GRASS plugin (I plan to try it for my next  
>> GIS Libs for Mac OS X).
>
> Right.
>
I'll probably keep doing the weak-link thing for now, until I figure  
out the plugin mechanism.


-----
William Kyngesburye <kyngchaos at kyngchaos.com>
http://www.kyngchaos.com/

First Pogril: Why is life like sticking your head in a bucket filled  
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Second Pogril: I don't know.  Why IS life like sticking your head in  
a bucket filled with hyena offal?
First Pogril: I don't know either.  Wretched, isn't it?

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