== Database cleanup queries ==

All entities with more than one CURRENT_VERSION:
{{{
select count(*) as cnt, id, node_type from openmind.node
where system_status = 'CURRENT_VERSION'
group by id
having cnt > 1
order by cnt desc;
}}}

All relations without source or target:
{{{
select * from openmind.node where node_type = 'RELATION' and (source_id is null or target_id is null);
}}}

All relations with target pointing at nonexistent entity:
{{{
select * from openmind.node rel 
left outer join openmind.node ent
on rel.target_id = ent.id
where 
rel.node_type = 'RELATION'
and ent.id is null;
}}}

All current relations pointing at non-current target entities:
{{{
select * from openmind.node rel, openmind.node ent 
where 
rel.target_id = ent.id
and rel.target_modif = ent.modification_time
and rel.system_status = 'CURRENT_VERSION'
and ent.system_status != 'CURRENT_VERSION';
}}}