I have a simple KV store implemented in a DB and I have a following code running inside a (outer) transaction (in my case it's Spring's Transactional but the concrete way doesn't seem to matter):
in_new_txn { kvService.save(KeyValue("key", 1)) }
val res1 = repo.read("key").value
in_new_txn { kvService.save(KeyValue("key", 2)) }
val res2 = repo.read("key").value
The key is a PK (@Id) of the KeyValue entity so one would expect a following "logical" sequence of DB queries:
BEGIN
BEGIN
select * from kv where key = "key"
insert into kv values ("key", 1)
COMMIT
select * from kv where key = "key"
BEGIN
select * from kv where key = "key"
update kv set value=2 where key="key"
COMMIT
select * from kv where key = "key"
COMMIT
Everything happens as expected, except the last select is for some reason ommitted, therefore res2 is 1 instead of 2.
Is this expected? For me not, i.e. I would expect a similar behaviour akin to the DB "read commited" transaction isolation level. That is the outer transaction sees all changes commited by other transactions meanwhile.
If it is expected how I can achieve the intended behaviour?
