begin transaction locks out other connections

Hello everybody, I have searched for a long time about this issue but I
was not able to find what is the cause. Maybe because I have not been
able to identify the right keywords.

We are experiencing the following problem using postgres8.3 and postgres8.1
On client1 we execute

begin;
insert into table1

and a message of correct execution for both statements is returned

On client2 we execute

begin;
insert into table2

and the client receives a correct execution message for the begin stmt
but waits for the insert statement until client1 execute either a commit
or a rollback.

The same happens with an insert on client1 and an update on client2 .
While there is no problem with an insert on client1 and a select on client2.

We have experienced the same problem either using pgAdmin as a client or
the jdbc driver.
So it seems the problem is on the db server: we experienced the same
problem on different installations of the same server on different
operative system.

Of course I'm colling this a problem beacuse there would be no need of
transaction support if request would be strictly serialized.

Thank to anyone has payed attention to this message.

_
_ <http://www.archicoop.it/>__ <http://www.archicoop.it/>