[postgis-users] Tiles

[Joan]

In a case where I use ST_SummaryStats I would like to have statistics of
the coverage, so I should have the coverage as one tile. Isn't
it inconvenient for a user to have several tables of the same coverage?

On 8 November 2011 18:01, Pierre Racine <Pierre.Racine at sbf.ulaval.ca> wrote:

> Briefly the ST_Intersection(rast, geom)  vectorize the raster in order to
> make a standard vector/vector intersection afterward. Since vectorizing is
> a slow process, a query involving ST_Intersection() is always more
> efficient with smaller tiles.
>
> Pierre
>
> > -----Original Message-----
> > From: postgis-users-bounces at postgis.refractions.net [mailto:
> postgis-users-
> > bounces at postgis.refractions.net] On Behalf Of Joan
> > Sent: Tuesday, November 08, 2011 11:56 AM
> > To: PostGIS Users Discussion
> > Subject: Re: [postgis-users] Tiles
> >
> > Yes, I have been doing an analysis with the same raster file but
> different tile sizes
> > and I get different results e.g st_intersects(rast, geom) . I would like
> to know
> > what the tile size has to do with the query results or performance.
> >
> >
> >
> > On 8 November 2011 17 <tel:2011%2017> :30, Pierre Racine
> > <Pierre.Racine at sbf.ulaval.ca> wrote:
> >
> >
> >       I guess you mean "raster tile"?
> >
> >       > -----Original Message-----
> >       > From: postgis-users-bounces at postgis.refractions.net [mailto:
> postgis-
> > users-
> >       > bounces at postgis.refractions.net] On Behalf Of Joan
> >       > Sent: Tuesday, November 08, 2011 10 <tel:2011%2010> :19 AM
> >       > To: PostGIS Users Discussion
> >       > Subject: [postgis-users] Tiles
> >
> >       >
> >       > Hello,
> >       >
> >       > I would like to know what the idea behind tiles is.
> >       >
> >       > Regards
> >       >
> >       > Joan M
> >
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> >
> >
>
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