Hi France,Instead, I get java.lang.ArrayIndexOutOfBoundsException.Could you send us the full stack trace?I was testing this on 9.2.3.Can the problem be reproduced with 9.3.1?Also a side question, is there a way to rewrite this query so not all DBs are locked? I get lock: global. I would like to lock only DBs that start with 'index-prompt-'Currently no (unless you explicitly open all those databases in your query). See [1] for more information.Best,Christian