Janusgraph filter query sometimes not served by index.

[etiennedi]

Steps to reproduce

1. Import 50 to 100k things
2. Run simple filter query, such as

{
  Local {
    Get {
      Things {
          Place (where: {
          path: ["geoLocation"],
          operator: WithinGeoRange,
          valueGeoRange: {
            geoCoordinates: {
              latitude: 48.5,
              longitude: 9.2,
            },
            distance: {
              max: 20.00
            }
          }
        }) {
          name
        }
      }
    }
  }
}

Expected Results

The query is efficient, as Janusgraph makes proper use of its indices

Actual results

The query is very inefficient, Janus decides to iterate over the entire Graph.

Analysis

It seem the following query runs fine:

.and(has("prop_17", geoWithin(Geoshape.circle(48.462761, 8.412090, 20.000000))))

However, the query we use, doesn't:

.union(has("prop_17", geoWithin(Geoshape.circle(48.462761, 8.412090, 20.000000))))

Criticality

When fixed, the fix needs to become available for 0.16.x, 0.17.x, 0.18.x and 0.19.x.

[etiennedi]

As outlined in the analysis section, I'm investigating now whether we can simply replace the union() with and() in the affected queries.