m> Now the main reason for not to switch is that if it will hang
m> again, we will have to kill a lot of connections.

On Windows, you can handle this with "ProcessExplorer"; I think there
should be a similar tool for Linux.

m> Besides - SS should work anyway.
But CS can do a time consuming garbage collection whilst other
processes are still running other database tasks.

Remember that "sweep" is not the 100% equivalent to "garbage
collection".

Turning off automatic sweep intervals, in conjunction with how your
client applications are probably handling transaction management (1
per statement) and the general behaviour of them (a lot of deletes, or
uncommitted or rolled back transactions) could even have made it worse
for you.

ciao,
André