Oracle 21c

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alter session set nls_date_format='yyyy-mm-dd'
create table tgt (
  dt, id, val
) partition by range(dt)
  interval (interval '1' month) (
  partition pmin values less than(date '2020-01-01')
)
as
select
  date '2020-01-01' + (interval '15' day)*level,
  level,
  cast(level as varchar2(20))
from dual
connect by level < 30
select *
from tgt
partition for(date '2021-01-01')


DT
ID
VAL


2021-01-10
25
25

2021-01-25
26
26


create table stg
for exchange with table tgt
insert into stg
values(date '2021-01-15', 0, 'updated')
1 rows affected

alter table tgt
exchange partition for(date '2021-01-01')
with table stg without validation
select *
from tgt
partition for(date '2021-01-01')


DT
ID
VAL


2021-01-15
0
updated


select *
from stg


DT
ID
VAL


2021-01-10
25
25

2021-01-25
26
26