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Does geomesa support aggregation functions?. Like 1.

  1. Calculating matching feature COUNT for the given query.
  2. Max/Min of an attribute for specified query collections.
  3. Avg of an attribute value for specified query collections.

I tried with geotools aggregate functions but they are not getting updated for new records being inserted. I also tried using offset for the feature but It's not working(as was suggested by one of the developers that geomesa doesn't support offsets). What can be done to achieve such operations?

Suresh Prajapati
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1 Answers1

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You could use the GeoMesa Spark formats, then use Spark built-in summary statisitics. See these spark mllib doc.

Also for version 1.3.2 it looks like more summary statistics are being added server-side. See this commit. That will be more efficient than Spark.

vpipkt
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  • Ok, I am new to spark, but would like to know why you mentioned summary statistics will be more efficient than spark. – Suresh Prajapati May 19 '17 at 07:28
  • Because they are accumulo iterators they execute on the data in place in the tablet servers to the greatest possible extent. A well managed spark job should have good localization too, but spark doesn't guarantee that. A lot will depend on how spark is deployed and configured. So more efficient from a Dev/devops perspective to use the stats iterators. – vpipkt May 19 '17 at 09:42