10.4.2 General statistics

select count(distinct dr2_source_id)
from edr3.dr2_neighbourhood as xm
left outer join edr3.gaia_source as gaia3
  on xm.dr2_source_id = gaia3.source_id
where gaia3.source_id is null

select count(distinct dr2_source_id)
from edr3.dr2_neighbourhood as xm

select count(distinct dr2_source_id)
from edr3.dr2_neighbourhood as xm
where angular_distance < 100