pgadmin3 and tomcat hangs.

using (tomcat with a connection pool max=20, postgres with max
connections set to 100)

Sometimes we will look into the database using pgadmin3 and will want
to add a column to a table. The webapp is NOT in use at the time (its
running and has 5 connections in the pool) but no one is logged in and
no one is actively using the connections. When I click OK to change
the table it will hang. When I bounce tomcat pgadmin3 returns and has
completed its job.

What causes this hang?

Also when I shutdown postgres I often have to shutdown with -m fast
because the shutdown would wait forever. Again the web app is running
but no activity is on the connections. When tomcat is bounced the
shutdown would proceed.

These are not show stopper issues but i am wondering if whatever is
causing the pgadmin to freeze could be causing our web app to
experience SocketTimeout exceptions once or twice a month. When these
exceptions occur (specified in another post on this list) we are NOT
doing any maintenance or even viewing the database through any
external tools. The last one occured at 11:30pm whan a user tried to
access the system.

thanks

Doug

--
What profits a man if he gains the whole world yet loses his soul?