[gdal-dev] RFC 29: OGR Set Desired Fields

[Frank Warmerdam]

Martin Dobias wrote:
> Another reason for going with SelectFields instead of SetIgnoredFields
> might be that in case a new special field OGR_FOO will be introduced
> in future version, it will be ignored implicitly when using
> SelectFields, while with SetIgnoredFields the client will have to
> explicitly put it into the list.

Martin / Daniel,

I would have seen this exactly the other way around!  I would prefer
the default is that new "special fields" come through and only be
ignored if requested specially.   What if it was determined at some
point that fetching the real FID was sometimes expensive and that in
cases where it does not matter we would like to be able to skip that.
Should we then start dropping the FID for everyone who has ever used
SelectFields() without knowing that some day FID would become optional?

I can live with SelectFields(), but to me it is an approach at odds
with trying to ensure backwards/forwards compatability for applications.

Best regards,
-- 
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I set the clouds in motion - turn up   | Frank Warmerdam, warmerdam at pobox.com
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