We currently have about 35000 process instances (JBPM 3.0) in our database (Oracle 10G) and observe the tablespace growing and growing in a very fast pace. The tables that grow fastest by far are JBPM_LOG, JBPM_VARIABLEINSTANCE and JBPM_BYTEBLOCK (all 3 together need about 60% of the total tablespace). As we are not really interested in the old values of the variables and log, but still want to keep the process instance, we want to establish a database job that regularly cleans those tables. Therefore I wonder if there is a risk deleting all values from those tables that belong to a process instance that is already finished (END_ is not null). I'm pretty sure that deleting JBPM_LOG does not have any affect, but I'm not sure whether deleting values from the other tables will affect running parent-processes altough the sub process is already finished.