[postgis-devel] [PostGIS] #2122: [raster] Real extent feature lost after metadata as views

[Sandro Santilli]

On Fri, Nov 30, 2012 at 08:37:35AM -0800, Bborie Park wrote:
> On Fri, Nov 30, 2012 at 8:28 AM, Sandro Santilli <strk at keybit.net> wrote:

> > You could just make the test looser... no tile can be fully outside
> > the real extent, and in no way above or on the left. Can overlap on
> > the right and on the bottom, but not be fully outside.
> > Should be fast.
> 
> That would be doable.  Extent constraint could be of the "true" data
> extent and the check is purely an intersects test instead of within.

I think it can use the operators, there are operators that can exactly
replicate the constraint that NO tile should go _above_ or
_on_the_left_of_ or _fully_on_the_right_ or _fully_on_the_bottom_.

> This constraint would only be able to be easily set at loading time
> through raster2pgsql as doing it within the database would require
> inspecting every band of every tile.

Yes, I think it should be a special function "raster_set_regular_blocking"
kind of thing, taking care of all it takes.

> raster2pgsql -t WIDTHxHEIGHT
> 
> That is how to specify tiling.  There is nothing to specify regular
> blocking as regular blocking is a constraint applied later.
> Constraints are applied using AddRasterConstraints().

Sounds like a pretty generic name, how does it distinguish between regular
blocking and irregular ones ? No constraints for irregulars ?

--strk;