<p dir="auto">Is this captured in the metadata database already and just a matter of surfacing it in the API call, or is it not captured outside of the segments themselves?</p>
<p dir="auto">Storing aggregatorFactories in segment metadata will make it possible to reindex existing segments without having to provide the original aggregators out-of-band. As a bonus, it would also be nice to store the QueryGranularity used for indexing. This isn't required for reindexing, since it would work fine to use QueryGranularity.NONE, but it would still be cool.</p>