Idea for grouping

group.graphql

###
# The result below shows the sum of population of all cities.
###
{
  Local {
    Get(where:{
      operands: [{
        path: ["Things", "City", "population"],
        operator: GreaterThan
        valueInt: 1000000
      }]
    },{
      group:{
        operands: [{
          path: ["Things", "City", "population"],
          aggregate: SUM # other options: COUNT, MAX, MIN, SUM, AVG, 
        }]
      }
    }) {
      Things {
        City {
          population
        }
      }
    }
  }
}

That indeed sounds reasonable. Not necessarily in favor for one or the other but syntactically it might absolutely be preferable to introduce a Stats{} function.

Naming wise, maybe Aggregate{} would suit better. Any thoughts @laura-ham and @moretea?

It would also be possible to add all aggregation functions as GQL-functions.

{
  Local {
    Aggregate(where: { ... }) { # or Stats...
      Sum{}
      Percentile{}
      Count{}
      Average{} 
      Maximum{}
      Median{}
      Minimum{}
      Mode{}
      GroupBy() {} # Would be used for more complext group by functions.
  }
} 

@moretea would it be fair to say that splitting these aggregate functions (except for GroupBy()) would be relatively easier to implement?

Maybe they are simple to implement. I would expect so, based on my experience with SQL. However, Gremlin is not as well rounded, and I did not research this yet for Gremlin.