Postgresql UPDATE LOCKS unrelated rows.

Hi,

We are using postgresql 7.3.2 on lunux platform. We performed locking
test as follows via JDBC:

Started 2 concurrent transaction with autocommit false and isolation
READ_COMMITTED :

Transaction 1:
===========
Update row 1
Sleep for 30 seconds
commit:

Transaction 2:
===========
Updated row 10000
commit

The second update had to wait for the first update operation to finish.
We also made sure that the 2 unrelated rows are not on the same page.

Is this expected behavior ?
Does update lock the whole table ?

Regards,
Ravi

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