Deadlock like scenario

Hi,

I am experience the problem where locks acquired by postgres are NOT getting
released.

The use case is something like:-

. There is a table let's say "A" and the trigger is created on this
table let say "A_TRIGGER".

. The trigger captures the data change happens in table A into table
B.

. There would be a huge insert, update, delete on table A, the side
effect of it table B also get updated very frequently.

. There is periodic job that runs every midnight to do full vacuum
and re-indexing on table B (but NOT on table A).

. It has been found that the queries are hanging and never completes
when there are some operation on table A.

Can someone please help me out to resolve this problem. If someone need more
information on this then please let me know.

Thanks in advance,

Shridhar