USE tewiki_p;

SELECT actor_name, actor_user,

    count(actor_name) as Edit_count, 

    SUM(abs(CAST(rev.rev_len as signed)-if(rev.rev_parent_id=0,0,CAST(parent.rev_len as signed)))) AS Gross_byte_count, 

    SUM(CAST(rev.rev_len as signed)-if(rev.rev_parent_id=0,0,CAST(parent.rev_len as signed))) AS nett_byte_count

FROM revision rev

left join actor ON actor_id = rev.rev_actor

left JOIN revision parent

ON parent.rev_id = rev.rev_parent_id

left JOIN page

ON page_id = rev.rev_page

WHERE page_namespace = 0

    and substr(rev.rev_timestamp,1,4)="2020"

    AND actor_user IS NOT NULL

GROUP BY actor_name

order by Gross_byte_count desc

limit 10000