Vector: 2 edges are created for proximity, while only one is needed

[lvca]

After loading the GloVe test database in Studio I noticed this:

Each Word vertices is connected with 2 Proximity edges. This is not necessary, because in ArcadeDB edges are bidirectional.

This means we could:

1. add a check when I create a Proximity edge: if the edge exists from the other side, skip it and
2. query always both directions

By reducing to half the number of edges means much faster insertion, query and less RAM used.

[lvca]

It's not that easy: once one edge is created, the creation of the opposite edge has a more elaborated algorithm:

arcadedb/engine/src/main/java/com/arcadedb/index/vector/HnswVectorIndex.java

Line 366 in dad3cff

newNode.newEdge(edgeTypeName, selectedNeighbourId, false);

[lvca]

Explore using lightweight edges instead.

[lvca]

This is not necessary anymore.