Oracle 18c

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create table DEMO(id int primary key, a int not null, b int);
insert into DEMO values(1,1,1);
1 rows affected

insert into DEMO values(2,2,2);
1 rows affected

commit;
update DEMO set b=b+1 where a=1;
1 rows affected

declare 
 pragma autonomous_transaction;
 r sys_refcursor;
begin
 -- read access the row that is not locked
 open r for select * from DEMO where a=2;
 dbms_sql.return_result(r);
 -- read access the row that is locked
 open r for select * from DEMO where a=1;
 dbms_sql.return_result(r);
 -- write access on the row that is not locked
 delete from DEMO where a=2;
-- write access on the row that is locked
 delete from DEMO where a=1;
 commit;
end;
/
ORA-00060: deadlock detected while waiting for resource
ORA-06512: at line 14