Changed - Use Collection.estimated_document_count() (which is a metadata query) instead of Collection.count_documents() (which is a full collection scan) in CatalogQuery ctor. The latter can be quite slow for large catalogs.
2.4.0
Added - Experimental support for searches against LIGO-style GW contours
Changed - ra_key and dec_key are actually optional for sphere2d-indexed catalogs. For healpix-indexed catalogs, the key names are taken from meta.keys.