figuring out why the dbfiles table gets so big

summarize_dbfiles.sql

select extract(year from created_at) as year, container_type, count(*) as n from dbfiles where id between 1000000000 and 2000000000 group by container_type, year order by container_type, year;

select created_user_id, container_type, count(*) as n from dbfiles where id between 1000000000 and 2000000000 group by container_type, created_user_id order by n desc;

select * from dbfiles where created_user_id is not null;

select extract(year from created_at) as year, created_user_id, container_type, count(*) as n from dbfiles where id between 9000000000 and 10000000000 group by container_type, created_user_id, year order by year, container_type, created_user_id;

select null as year, created_user_id, container_type, count(*) as n from dbfiles where id between 9000000000 and 10000000000 group by container_type, created_user_id order by container_type, created_user_id;

select count(*) from dbfiles where container_type = 'Posterior';
select count(distinct container_id) from dbfiles where container_type = 'Posterior';

select count(*) as n, container_id from dbfiles where container_type = 'Posterior' group by container_id order by n desc;

select * from dbfiles where container_id = 1000000032;

select count(*) from dbfiles where container_type = 'Input'; --462,801
select count(distinct container_id) from dbfiles where container_type = 'Input'; --374,782
select count(distinct file_name) from dbfiles where container_type = 'Input';--400,000
select count(distinct file_path) from dbfiles where container_type = 'Input';--208,961

select count(*) as n, file_path from dbfiles where container_type = 'Posterior' group by file_path order by n desc;