Hur man jämför grupper av tupler i sql

Något så här

create table t1 (group_id varchar2(20), value varchar2(20));
create table t2 (group_id varchar2(20), value varchar2(20));

insert into t1 values ('A','FOO');
insert into t1 values ('A','BAR');
insert into t1 values ('X','HHH');
insert into t1 values ('X','ZOO');
insert into t2 values ('C','FOO');
insert into t2 values ('C','BAR');
insert into t2 values ('B','ZOO');


select t1.group_id t1_group,t2.group_id t2_group, 
      --t1.all_val, t2.all_val, 
       case when t1.all_val = t2.all_val then 'match' else 'no match' end coll_match
from 
  (select 'T1' tab_id, group_id, collect(value) all_val, 
          min(value) min_val, max(value) max_val, count(distinct value) cnt_val 
  from t1 group by group_id) t1
full outer join
  (select 'T2' tab_id, group_id, collect(value) all_val, 
          min(value) min_val, max(value) max_val, count(distinct value) cnt_val 
  from t2 group by group_id) t2
on t1.min_val = t2.min_val and t1.max_val = t2.max_val and t1.cnt_val = t2.cnt_val
/

Jag har gjort en preliminär eliminering baserat på lägsta, maximala och antalet distinkta värden i varje grupp, vilket skulle hjälpa till med stora datamängder. Om datamängderna är tillräckligt små kanske du inte behöver dem.

Det säger dig matcherna. Du behöver bara trycka ut det ett extra steg för att hitta de grupper som inte har några matchningar

select t1_group
from
(
  select t1.group_id t1_group,t2.group_id t2_group, 
        --t1.all_val, t2.all_val, 
         case when t1.all_val = t2.all_val then 'match' end coll_match
  from 
    (select 'T1' tab_id, group_id, collect(value) all_val
    from t1 group by group_id) t1
  cross join
    (select 'T2' tab_id, group_id, collect(value) all_val
    from t2 group by group_id) t2
)
group by t1_group
having min(coll_match) is null
/

select t2_group
from
(
  select t1.group_id t1_group,t2.group_id t2_group, 
        --t1.all_val, t2.all_val, 
         case when t1.all_val = t2.all_val then 'match' end coll_match
  from 
    (select 'T1' tab_id, group_id, collect(value) all_val
    from t1 group by group_id) t1
  cross join
    (select 'T2' tab_id, group_id, collect(value) all_val
    from t2 group by group_id) t2
)
group by t2_group
having min(coll_match) is null
/