> that the only way to find the current mode read is either use > event 10046 (when the blocks are not already cached) or check > x$bh for increase in touch count (class 4 for segment header, > verify with file and block number). There's no event to trace > CU read. I posted that before I read Fuyuncat's posting at http://www.hellodba.com/Doc/logic_io_secret_FTS_1.html It looks like setting _trace_pin_time to non-zero unambiguously pinpoints the buffers read in current mode. Excellent! BTW, for the benefit of others, the meanings of some of the logical I/O functions Fuyuncat used are explained at http://www.jlcomp.demon.co.uk/buffer_usage.html Yong Huang -- //www.freelists.org/webpage/oracle-l