select event_entity,
        event_type,
        sum(if(page_id is null, 1, 0)) as null_page_id,
        count(1) as total
   from wmf.mediawiki_history
  where snapshot='2020-06'
    and event_entity in ('page', 'revision')
  group by event_entity,
        event_type
;

 select event_entity,
        event_type,
        event_user_id,
        event_user_text_historical,
        event_timestamp,
        page_id,
        revision_id,
        user_id
   from wmf.mediawiki_history
  where snapshot='2020-06'
  group by
        event_entity,
        event_type,
        event_user_id,
        event_user_text_historical,
        event_timestamp,
        page_id,
        revision_id,
        user_id
 having count(1) > 1
;

 select *
   from wmf.mediawiki_history
  where snapshot = '2020-06'
    and wiki_db = 'enwiki'
    and event_entity = 'user'
    and event_type = 'alterblocks'
    and event_user_id = 1272505
    and event_user_text_historical = 'ST47'
    and event_timestamp = '2009-02-04 03:59:18.0'
    and wiki_db = 'enwiki'
    and user_id = 6144686
  limit 1000
;