[postgis-devel] temporal indexing

[Elena Camossi]

In fact my first intention was to evaluate the performances of the two
different cases: querying time and space with separate index, and then with
a unique spatio-temporal index.
Do spatio-temporal queries, in this second case, can be performed even if
the spatial and temporal query data are stored as separate column? Or is
this cube type a special data type with a related index type?
In my spatio-temporal schema are even defined in different tables, that have
to be joined when executing the access query.

Best regards,
-Elena

On 8/7/07, Chris Hodgson <chodgson at refractions.net> wrote:
>
> You didn't mention if you would be doing spatio-temporal queries, ie.
> querying for objects which existed within a certain region of time and
> space. For these types of queries, the cube type and index which is
> provided in the postgres-contrib package is quite effective. You can
> store your x,y coordinates in the first two dimensions of the cube,and
> the date/time in the third dimension. The gist-based cube indexes are
> are very fast, but do consume a lot of disk space.
>
> If you're only querying based on date then a standard b-tree index on
> the date itself should provide reasonable performance.
>
> Chris
>
> Elena Camossi wrote:
> > Hi list,
> >
> > I'm designing a spatio-temporal schema with support for coverage and
> > temporal data in postgresql by using postgis spatial extension. The
> > temporal support so far is quite limited,  just timestamps which state
> > the time at which data have been collected. Anyway, the temporal
> > information is extensively used to access data, so the corresponding
> > fields should require an index.
> >
> > The scientific literature states that R-Tree perform quite well with
> > this kind of data, but there exist other indexes that should perform
> better.
> > Does anyone in the list has some previous experience on using GiST
> > postgres implementation for indexing postgresql temporal columns? Does
> > anyone extend the GiST operator classes with specific support for
> > temporal data?
> >
> > Thank you for helping.
> >
> > Best regards,
> > -Elena
> >
> >
> > ------------------------------------------------------------------------
> >
> > _______________________________________________
> > postgis-devel mailing list
> > postgis-devel at postgis.refractions.net
> > http://postgis.refractions.net/mailman/listinfo/postgis-devel
>
> _______________________________________________
> postgis-devel mailing list
> postgis-devel at postgis.refractions.net
> http://postgis.refractions.net/mailman/listinfo/postgis-devel
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.osgeo.org/pipermail/postgis-devel/attachments/20070808/20554b3d/attachment.html>