<br /> Hi,<br /> I am trying to understand concurrency and mvcc with a small example in psql.<br />Isolation_level is
readcommited. There are 4 psql session by the same Role. I am executing the commands in the below sequence.<br /> <br
/>Session 1:<br />insert into kentab values ( 1,'A');<br />commit; <br /> begin;<br />update kentab set name='Ad' where
id=1;<br/><br />session 2: <br />begin;<br />update kentab set name='A2d' where id=1;<br /><br />session 3: <br
/>begin;<br/>update kentab set name='A3d' where id=1;<br /> <br /> Session 1:<br />commit;<br /><br />session 4:<br
/>begin;<br />update kentab set name='A4d' where id=1;<br /><br />I want to now commit in Session 3. <br />Firstly I
don'tsee the command prompt. <br />Morever, despite executing commit; it is not commiting and ending before session2 or
session4.<br/>I have tried Select for Update too but it is behaving the same.<br /> <br /> Any clue what must be
happeninghere?<br /> <br /> Thanks,<br /> Ken<br /><br /><br /><hr />Fly HYD-BLR for Rs.499 Log on to MakeMyTrip! <a
href="http://ss1.richmedia.in/recurl.asp?pid=266"target="_new">Check it out!</a>
