My site has an ADSM server running under MVS at service level 3.1.2.20. I have
been trying to understand the more arcane capabilities of the select command.
I executed the following command earlier today:

select volume_name, devclass from volumes, stgpools where
 volumes.stgpool_name=stgpools.stgpool_name

The server hung. The administrative client session I was using became totally
unresponsive. When I attempted to start another administrative client session
the password prompt never appeared. When I issued a command using the MVS
modify command the ADSM command was echoed to the console but nothing else
ever happened. An MVS stop command failed to bring down the server. I finally
resorted to the MVS cancel command. I was able to bring up the server again
with no sign of unusual behavior. It may be significant that there was a 'move
data' process running when the hang occured.

I am now decidedly nervous about running complex select commands. Does anyone
have any information on the dividing line between select commands that are
safe and select commands that cause hang conditions?

This is only one of several annoying bugs I have run into lately. Why is there
so much sloppy workmanship in the current ADSM code?