John Novak wrote:
I have a large number of rows containing metadata about rater files
sitting in a PostGIS table. Each row is associated with a georeferenced
file sitting in a file system, and the row contains polygon geometry
representing the footprint of the raster. The rows also contain many
other attributes that I'd like to use to filter the displayed rasters.
Having the functionality of the RASTER layer, but using a PostGIS table
as a source for features rather than a SHAPEFILE would be a very useful
thing, at least in my case.
>
What's the opinion regarding
1. the overall usefulness of such a beastie
and
2. the complexity of actually implementing said beastie, given that
it's a combination of the functionality of a PostGIS layer and a RASTER
layer ?
I admit I have not done my homework and really examined the code for
these two layers.
John,
It is currently possible to use a postgis table as a "tile index" for
a raster layer. To do so, configure the postgis table as a distinct layer,
and use the name of that layer in the TILEINDEX keyword of your raster layer
instead of the name of an external shapefile.
The raster layer will do a spatial query on the tileindex table to get
a list of rasters to plot.
I'm a bit fuzzy on how you would do other sorts of query operations.
It is possible a FILTER on the tileindex layer will be preserved as
part of the tileindex query, but I'm not absolutely sure. Of course,
you could put complex query logic right into your DATA statement on
the postgis layer.
Best regards,
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