Hi Claudia, Claudia Zeiler schrieb: > Do you know how many parallel processes are trying to run? We had this wait > event. > It turned out that we were trying to create indexes as 'parallel' without specifying the degree. >Oracle defaulted to 57 processes, and we had a FIGHT on our hands. 27 actually managed to run, and the others > waited on the PX Deq Credit: send blkd wait event. Maybe you too have more > parallllllel ism than you intended. There are many parallel hints in the statement, I guess about 30 :) The system itself has 114 parallel processes (ora_p*) ATM. One explanation I'd consider as possible is, that the MERGE itself spawns less p-processes than the sub-selects, so that the select's p-processes (the producers) are too fast for the merge (consumer). But this is a guess, and it would ge great to see some reliable method to track this issue down :) Regards Martin -- Usn's IT Blog for Linux, Oracle, Asterisk http://www.usn-it.de -- //www.freelists.org/webpage/oracle-l