[Qgis-developer] GDAL 2.1 can update Geojson files - What is missing in QGIS to edit GeoJSON files ?
matthias at opengis.ch
Thu Jan 14 09:04:00 PST 2016
On 01/14/2016 05:42 PM, Even Rouault wrote:
>> It will benefit from expression compiling (for filtering and order by)
>> which results in performance improvements when it can be applied.
> I'm not completely sure to know what you refer to in the QGIS context but the
> OGR SetAttributeFilter() method is directly evaluated by the SQLite request
> engine as a WHERE clause, and similarly for the ExecuteSQL() API.
It tries to compile QgsExpressions to native SQL syntax.
I think the point of using OGR that it offers an awesome abstraction
layer where the consumer doesn't need to care about the backend.
As soon as ExecuteSQL is used this abstraction no longer applies and it
just adds another layer of uncertainty (different library versions...)
and may potentially hide internals of the backends which may be useful
in some cases (datatypes, backend metadata, available indexes, ...), so
the advantage is gone while it complicates advanced topics.
Or did I miss something?
>>>> All the best
OPENGIS.ch - https://www.opengis.ch
Spatial • (Q)GIS • PostGIS • Open Source
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