* Open two database consoles and use the following queries in them:
```
1 begin; 2 select txid_current(); 3 insert into t (col) values ('test') on conflict (col) do nothing; 4 commit;
```
I ran 1 and 2 in both. It worked for both. And then I ran query 3 in the first console. It worked. After that I ran query 3 in the second console. It got stuck! When I commit the tx in first console, the stuck query in second console finishes The transaction isolation level is 'read committed'.
