Once DM-5533 lands, a new interface for partitionings of the unit sphere, Pixelization, will be available, along with a class capable of efficiently storing integer sets (RangeSet). It is worth thinking about whether the Chunker class, which implements the Qserv partitioning scheme, should be expressed in terms of this new interface. (The way I imagine this would work is to stuff the chunk ID of a point into the upper 32 bits of a 64 bit index, and the sub-chunk ID into the lower 32 bits). This is an API change that would impact the Qserv codebase, but that may be worthwhile as it would make it easier to swap out partitioning strategies later.