We're trying to find a hot block: select p1 "File #", p2 "Block #", p3 "Reason Code" from v$session_wait where event = 'buffer busy waits'; File # Block # Reason Code ---------- ---------- ----------- 304 2 13 (File block header) 304 2 13 ..... Here's the issue, there is *no* file# 304. There are only 240 datafiles in the database and only a handful of temp files. 304 matches neither the file_id nor relative_fno in dba_data_files. Nothing maps to that in dba_segments either. Is this a bug, or are we doing something wrong here? Chris Newman Database Specialist AITS, University of Illinois -- //www.freelists.org/webpage/oracle-l