[postgis-devel] [PostGIS] #1319: [raster] Make raster_columns a view and AddRasterColumn enforce more

[PostGIS]

#1319: [raster] Make raster_columns a view and AddRasterColumn enforce more
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 Reporter:  robe            |       Owner:  robe         
     Type:  task            |      Status:  new          
 Priority:  high            |   Milestone:  PostGIS 2.0.0
Component:  postgis raster  |     Version:  trunk        
 Keywords:                  |  
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Comment(by robe):

 Nothing would be constrained using typmod for the raster case, it would
 all be constraint based and still use AddRasterColumn.  If you can't fit
 everything you need to constrain in typmod, there is no point in using
 typmod at all.

 typmod is only useful if people can build a raster like:

 ALTER TABLE someraster_table ADD COLUMN rast
 raster(ARRAY['8BUI','8BUI','8BUI'], 4326,0.5,-0.5, ...);

 Since there is too much to define for raster, it can't use typmod or at
 least not until PostgreSQL expands on the space allowed.


 Alternatively users would be able to do

 ALTER TABLE someraster_table ADD COLUMN rast raster;

 populate their table.

 Then run something like a

 SELECT populate_raster_columns();

 Which would inspect the table data and apply constraints to the table
 based on the bandmetadata and metadata of the table.

 That is pretty much what populate_geometry_columns() does (well it
 defaults to typmod, and override for constraint).

 We might want to call it something different though since it is anow a
 misnomer since it really isn't populating any table.  It's adding
 contraints/typmodifiying the data.

 Hope I haven't confused you more.

-- 
Ticket URL: <http://trac.osgeo.org/postgis/ticket/1319#comment:2>
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