K Gopalakrishnan schrieb: > > Advanced Queueing process?? > > What is the value for aq_tm_processes in your instance? > both instances have aq_tm_processes set to 0 and we don't use AQ on these instances. maybe AWR or some other internal stuff use AQ but we don't. some more details: this O000 process hung while executing this statement: SELECT (CASE WHEN PERCENT_USED> 100 THEN 0 ELSE (100-PERCENT_USED) END) PERCENT_FREE FROM (SELECT (SUM(PERCENT_SPACE_USED)-SUM(PERCENT_SPACE_RECLAIMABLE)) PERCENT_USED FROM V$FLASH_RECOVERY_AREA_USAGE) in an anonymous pl/sql block. unfortunately this session caused a clusterwide hang (all rdbms instances on all nodes). i think, because it locked something inside ASM. after this session was terminated by an 600[17182] the whole cluster came back to life. Oracle Support is working on the issue, but i'm very curious, what this process is used for. thanks so far. regards, -ap -- //www.freelists.org/webpage/oracle-l