Oracle deadlock test

1, Build a test table

create table l (id int);insert into l values(1);insert into l values(2);

2, Perform lock test

Need to open 2 One session .

conversation 1	conversation 2
select * from l where id=1 for update;
	select * from l where id=2 for update;
select * from l where id=2 for update; ---- Wait for session 2 Submit .
	select * from l where id=1 for update; ---- Wait for session 1 Submit .
SQL> select * from l where id=2 for update; select * from l where id=2 for update * ERROR at line 1: ORA-00060: deadlock detected while waiting for resource
// You need to perform commit,rollback. conversation 2 Can be executed normally .

3,PG Lock test

conversation 1	conversation 2
begin;	begin;
select * from l where id=1 for update;
	select * from l where id=2 for update;
select * from l where id=2 for update; # Conversation waiting 2
	select * from l where id=1 for update;  # conversation 2 Report errors , conversation rollback; postgres=*# select * from l where id=1 for update; ERROR:  deadlock detected DETAIL:  Process 26109 waits for ShareLock on transaction 585; blocked by process 26104. Process 26104 waits for ShareLock on transaction 586; blocked by process 26109. HINT:  See server log for query details. CONTEXT:  while locking tuple (0,1) in relation "l" postgres=!# select * from l where id=2 for update; ERROR:  current transaction is aborted, commands ignored until end of transaction block postgres=!# select * from l where id=2 for update; ERROR:  current transaction is aborted, commands ignored until end of transaction block postgres=!# commit; ROLLBACK
# conversation 1 Normal execution . It's ok commit