Re: [geomesa-users] Any suggestions for indexing data with a duration?

[Chris Eichelberger <cne1x@xxxxxxxx>]

Beau,

GeoMesa should be able to get you most of the way through this use case.
By indexing based on location and one end-point of your time range, the
remainder of the range query can be handled via CQL.  That is, if I have
a feature that contains these fields
"geom:Geometry,start:Date,end:Date", then a query of the form
(simplified for presentation):

  geom INTERSECTS polygon
  AND start DURING dt0/dt1
  AND end BEFORE dt0/dt1

would both take advantage of the index on the (location, start-time)
pair, and would return all of the records whose time-span intersects the
dt0/dt1 interval.

If you find that's not working for you, please just let us know.

Thanks!

Sincerely,
  -- Chris


P.S.  We removed explicit support for the end-time attribute relatively
recently, but only because that field was never actually used in the
index.  Whether we add this field explicitly to the geo-time index in
the future probably depends on how our work on secondary indexes gels.


On Thu, 2014-06-26 at 16:21 +0000, Beau Lalonde wrote:
> All,
> 
> As I am using the latest GeoMesa I am coming up with some issues that hopefully others have already thought about.
> 
> Namely, I have data that inherently has a time duration (e.g. a start and end time), and I want to index that data using GeoMesa.  In an older version of GeoMesa I could index the data using both a start and end time, but the current version of GeoMesa only indexes data using a single time parameter.  Since time ranges do not seem to be supported by current GeoMesa, does anyone have a suggested approach?
> 
> Here is an abstract example for my problem:
> - I index data that inherently lasts from time 5 to time 10
> - I want to be able to perform a query that will return results if the query time range at all intersects/overlaps with the indexed data
> -- For example, I want to perform a query using the time range 6-7 and still get a result
> 
> My only thoughts are that since I can no longer index a time range, I must discretize my data and index each discretized portion - each with its own indexed time.  This may work in a practical sense, but will always succumb to the above abstract problem where a query that should return results does not return results because the indexed data is discretized.
> 
> Does anyone have any thoughts?
> 
> Is GeoMesa going to bring back support for indexing data that has a duration?
> 
> Thanks,
> 
> Beau
> 
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