Oracle 21c

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create table pod_label (
    name varchar2(256),
    key varchar2(256),
    value varchar2(256)
);
create table service_selector (
    name varchar2(256),
    key varchar2(256),
    value varchar2(256)
);
begin
insert into pod_label (name, key, value)
values ('p1', 'l1', '1');
insert into pod_label (name, key, value)
values ('p1', 'l2', '2');
insert into pod_label (name, key, value)
values ('p1', 'l3', '3');

insert into pod_label (name, key, value)
values ('p2', 'l1', '1');
insert into pod_label (name, key, value)
values ('p2', 'l3', '3');

insert into pod_label (name, key, value)
values ('p3', 'l1', 'N/A');

insert into service_selector (name, key, value)
values ('s1', 'l1', '1');
insert into service_selector (name, key, value)
values ('s1', 'l2', '2');
insert into service_selector (name, key, value)
values ('s2', 'l1', '1');
insert into service_selector (name, key, value)
values ('s3', 'l1', '1');
insert into service_selector (name, key, value)
values ('s3', 'l3', 'none');


commit;
end;/
1 rows affected

select *
from pod_label


NAME
KEY
VALUE


p1
l1
1

p1
l2
2

p1
l3
3

p2
l1
1

p2
l3
3

p3
l1
N/A


select *
from service_selector


NAME
KEY
VALUE


s1
l1
1

s1
l2
2

s2
l1
1

s3
l1
1

s3
l3
none


with vals_per_service as (
  /*Number of criteria per service*/
  select
    s.*,
    count(1) over(partition by name) as s_cnt
  from service_selector s
)
, pod_match as (
  select
    s.name as service_name,
    p.*,
    s.s_cnt,
    /*Number of matches per pod and service*/
    count(1) over(partition by s.name, p.name) as match_cnt
  from vals_per_service s
    left join pod_label p
    on p.key = s.key
    and p.value = s.value
)
select *
from pod_match
/*Pods that matched by all criteria*/
where s_cnt = match_cnt
--  or name is null /*If you want selectors without matches*/
order by 1,2


SERVICE_NAME
NAME
KEY
VALUE
S_CNT
MATCH_CNT


s1
p1
l1
1
2
2

s1
p1
l2
2
2
2

s2
p1
l1
1
1
1

s2
p2
l1
1
1
1