[pgpointcloud] uncompressed pointcloud size

[Paul Ramsey]

Impressive. Where there is a will, there is a way.
P 


--  
http://postgis.net  
http://cleverelephant.ca


On February 2, 2015 at 9:02:32 AM, Rémi Cura (remi.cura at gmail.com) wrote:
> Hey,
> in fact you can create a new schema with a different compression, and
> simply convert manually your data from old schema to new schema.
>  
> For this,
> you use pc_explode to convert old patch to old points, then
> pc_get on each attributes to get old double,
> then pc_makepoint() using the new schema, with an array of the old atributes
> then pc_patch to make a new patch.
>  
> It is definitively clumsy.
>  
> Converting patches form one schema to another is a feature hard to propose.
> Cheers,
> Rémi-C
>  
> 2015-02-02 17:49 GMT+01:00 Paul Ramsey :
>  
> > No, there’s no way to cast a patch from one pcid to another (yet). It’s an
> > obvious functionality hole, so it awaits and implementation. For now you
> > have to just reload with a different PDAL pipeline :/
> >
> > P
> >
> >
> > --
> > http://postgis.net
> > http://cleverelephant.ca
> >
> >
> > On February 2, 2015 at 8:47:38 AM, Sandro Santilli (strk at keybit.net)
> > wrote:
> > > On Mon, Feb 02, 2015 at 06:26:14AM -0800, Paul Ramsey wrote:
> > > > Not a bug.
> > > > The pcpatch type is declared with storage ‘external’, so pgsql doesn’t
> > attempt to compress
> > > it at all.
> > > > 65535 * 8 * 8 = 4194487, raw, uncompressed data.
> > > > The geometry type is declared with storage ‘main’, which does allow
> > pgsql to compress,
> > > if the size exceeds a page. So you’re seeing the post-zlib size when you
> > run pg_column_size.
> > >
> > > Thanks, everything makes sense now :)
> > > I've experimented with changing the storage and indeed
> > uncompressed/external
> > > is now comparable between geometry and pcpatch ( the former being
> > actually
> > > bigger, probably due to SRID and type being replicated in each component
> > > point ). Now I wanted to try different kind of compressions but I could
> > > not find any function to change the pointcloud_format id in a pcpatch
> > type,
> > > is there any such function ? Simply casting to a different type fails
> > > with an error (pcid not consistent).
> > >
> > > --strk;
> > >
> >
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> >
>