alter table conference_log add column users integer;
update conference_log set users = 0 where users IS NULL;
alter table conference_log alter column users set default '0';
alter table conference_log alter column users set NOT NULL;

alter table conference_log add column maxusers integer;
update conference_log set maxusers = 1 where maxusers IS NULL;
alter table conference_log alter column maxusers set NOT NULL;
alter table conference_log alter column maxusers set default '1';

