Oracle 18c

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create table A ( columnA )
as
select 'a' from dual union all
select 'b' from dual union all
select 'b' from dual union all
select 'c' from dual union all
select 'c' from dual union all
select 'c' from dual union all 
select 'e' from dual -- one 'e' in each table
;
7 rows affected

-- one 'a', 'b', 'c' (respectively) missing 
-- 4 x 'd' (does not exist in the other table)
create table B ( columnA)
as
select 'b' from dual union all
select 'c' from dual union all
select 'c' from dual union all
select 'd' from dual union all
select 'd' from dual union all
select 'd' from dual union all
select 'd' from dual union all
select 'e' from dual -- one 'e' in each table
;
8 rows affected

select 
  *
from (
  select unique 
    'table A ->' as tbl, columnA
  , count(*) over ( partition by columnA ) as instances_a
  from A
) A_
full join
(
  select unique 
    'table B ->' as tbl, columnA
  , count(*) over ( partition by columnA ) as instances_b
  from B
) B_
on A_.columnA = B_.columnA 
order by A_.columnA, B_.columnA
;


TBL
COLUMNA
INSTANCES_A
TBL
COLUMNA
INSTANCES_B


table A ->
a
1
null
null
null

table A ->
b
2
table B ->
b
1

table A ->
c
3
table B ->
c
2

table A ->
e
1
table B ->
e
1

null
null
null
table B ->
d
4


select 
  A_.tbl, A_.columnA, count_a
, B_.tbl, B_.columnA, count_b
, case
    when count_a = count_b then 'yes'
    else 'no'
  end as "column contents equal?"
from (
  select unique 
    'table A ->' as tbl, columnA
  , count(*) over ( partition by columnA ) as count_a
  from A
) A_
full join
(
  select unique 
    'table B ->' as tbl, columnA
  , count(*) over ( partition by columnA ) as count_b
  from B
) B_
on A_.columnA = B_.columnA 
order by A_.columnA, B_.columnA
;


TBL
COLUMNA
COUNT_A
TBL
COLUMNA
COUNT_B
column contents equal?


table A ->
a
1
null
null
null
no

table A ->
b
2
table B ->
b
1
no

table A ->
c
3
table B ->
c
2
no

table A ->
e
1
table B ->
e
1
yes

null
null
null
table B ->
d
4
no

TBL	COLUMNA	INSTANCES_A	TBL	COLUMNA	INSTANCES_B
table A ->	a	1	null	null	null
table A ->	b	2	table B ->	b	1
table A ->	c	3	table B ->	c	2
table A ->	e	1	table B ->	e	1
null	null	null	table B ->	d	4