Our one delivery unit (used as the main DU for production projects) is filling up with change lists (we're over 10k as far as the counter goes) and I have noticed that when I go to execute a transport and view released change lists, it now takes about 30 seconds to populate the CL's available to transport.
In the beginning, the list returned almost instantaneously, I figure the latency is caused by the sheer number of objects and change lists that are still being stored in some system table/view and that has grown to be very large, therefore is slow to query.
This can most likely be mitigated through multiple DU's but at the same time that all depends on how these changes are stored by the system.
My question is, is it possible to purge released (and already transported) change lists? Would this be a good idea (as far as best practices)