I am trying to understand concurrency and mvcc with a small example in psql.Isolation_level is read commited. There are 4 psql session by the same Role. I am executing the commands in the below sequence.
Session 1:insert into kentab values ( 1,'A');commit;
begin;update kentab set name='Ad' where id=1;
session 2: begin;update kentab set name='A2d' where id=1;
session 3: begin;update kentab set name='A3d' where id=1;
session 4:begin; update kentab set name='A4d' where id=1;
I want to now commit in Session 3. Firstly I don't see the command prompt. Morever, despite executing commit; it is not commiting and ending before session2 or session4.I have tried Select for Update too but it is behaving the same.
Any clue what must be happening here?
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