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Re: [geomesa-users] Updating/Deleting data

Hi Mathias,


Great question.  You’re right, each position is a feature in a point data source but you can also store the whole trajectory as a linestring feature if you so choose.  For a point feature, you can have an attribute that threads point features together into a trajectory and query using that attribute for the whole trajectory.  GeoMesa has optimized indexes for point features and for linestring/polygon features.  For linestring features, GeoMesa supports parallel arrays of attributes for storing information specific to each vertex of a linestring feature (speed, heading, etc).  Finally, GeoMesa natively handles GeoJSON where you have a lot of flexibility in how you model your data.  In general, there are lots of ways to handle rollups of sensor observations in trajectories.


With streams of sensor or observation data, usually one either wants to see a 'live' view (or do other online processing) or they wish to maintain an archive of the observations for later querying and analysis.  Given a stream of AIS observations, one may want to see where certain boats are now (perhaps to manage a fleet).  Historical analyses could answer questions about ships pattern of life, etc.


GeoMesa has a number of capabilities.  Using the Kafka DataStore, it is possible to show that up-to-date view of a stream.  The Kafka DataStore can be integrated with a stream processing platform like Apache Storm or Spark Streaming to provide online analysis.


GeoMesa leverages big databases (Accumulo, HBase, Cassandra, etc) for storing billions of records and providing batch analysis options.  GeoMesa has integration with Spark.  For the programmer, you can get access to RDDs of SimpleFeatures.  For an analyst, GeoMesa’s integration with Spark SQL allows for quick data discovery and visualization.

Cheers,

Jim

On 02/15/2017 11:18 AM, Mathias Herberts wrote:
Hi,

I have seen many examples of GeoMesa which display sequences of positions for ships coming from AIS data.

If my understanding of how GeoMesa indexes data is correct, each position is really a feature with its own feature id.

This makes me wonder how a position at a given time can be updated and how can a complete track be deleted.

The process of storing time series in GeoMesa seems kind of artificial and at the edge of what the tool suite was meant for initially.

If anyone could cast some light on those points...


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