yes... .by writing your own HQL query
An HQL delete query will not resolve Foreign Key dependencies (according to Hibernate docs). Since JBPM_LOG has FK's to itself for parent logs, I don't think that an HQL query will work. :(
Please tell me I'm wrong :)
hmmm.... works in 3.2.3 here afaics... so might be 3.1 related.
Sorry, pressed submit to soon...
If you make a small unittest, I'll check in 3.2.3 to see if the behaviour is different from your situation