[Qgis-developer] WFS Provider Strategies

[Even Rouault]

> True... Although we could replace the features in the cache instead of
> dropping the new ones for a tiny improvement.

That would indeed help for the next feature request

> 
> >>>> Question: *is **there anybody using WFS with this option unchecked?*
> >>>> And if yes, for what reason?
> >>> 
> >>> Yes it is needed for some use cases. There are servers that have buggy
> >>> behaviour with BBOX requests combined with other filters. Or the cost
> >>> of solving a spatial request might be super high, making it more
> >>> practical to issue a GetFeature without a BBOX.
> >> 
> >> Ok, so it should be a super well hidden checkbox with a big warning sign
> >> next to it?
> > 
> > That really depend on servers. If the current default behaviour is OK for
> > most, it might still be useful that the option is not too hidden if users
> > have issues with some servers. They might have a better chance of trying
> > to uncheck the option. Where would you hide it ?
> > Note: this is not new to 2.16 as far as I remember. The option was
> > already there.
> 
> Well, I was confused and I know of others which are confused.
> 
> At the moment it's really hard to tell which is the recommended option
> and which one is the "try this if your sever is broken" option. We could
> just add a warning if it's unchecked which says "only do this if there
> are problems with the default" or put it into an advanced dialog or so.
> Have you actually seen such servers? And if yes, can you name them?

The issues were with multiple layer joins with GeoServer in some circumstances not very
clearly understood ( I don't want to particularly point fingers at
GeoServer, as server side joins is a pretty advanced feature rarely implemented by servers)

You need to get an API key at
 https://data.linz.govt.nz/group/owner-data-controlled-access-group/

And then try the following SQL request

 SELECT DISTINCT
       par.id,
       par.status,
       own.owner_type,
       own.prime_surname,
       own.prime_other_names,
       own.corporate_name,
        par.shape
FROM
       "layer-1571" AS par
       JOIN "table-1569" AS tpa ON par.id = tpa.par_id
       JOIN "table-1564" AS own ON tpa.title_no = own.title_no
WHERE
       ST_Within(par.shape, ST_MakeEnvelope(174.806, -41.347, 174.846, -41.285, 'EPSG:4167’))

The server will not like the extra addition of the BBOX.

There might be less complicated examples but this is the one I managed to find quickly in my mail box...

Even

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