Making a tablespace read-only - identifying blocking tx

I am creating a stored proc that will export a tablespace. One task it needs to perform is to place the tablespace(s) in read only mode to make a copy. Based upon the application and proc logic, there should not be any transactions against objects in the ts. However, if there are, the ALTER TABLESPACE command will wait until the transaction is completed. I would rather have the ALTER TABLESPACE command fail immediately. If I cannot do that, I would like to be able to test for locks on objects in the tablespace
(figured that one out, but it is rather kludgy).
 

Is there a method to force an immediate failure of ALTER TABLESPACE <tsname> READ ONLY if it cannot be immediatly completed? Is there a clean method/proc to determine if the ALTER TABLESPACE command will work?  

Dan Fink

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Author: Fink, Dan
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