Ooops, I now look rather stupid... I know of the describe command, but SQLDeveloper 2.1 didn't let me describe the object (I was logged in as sys): select user from dual; desc x$ash; USER ------------------------------ SYS desc x$ash ERROR: ---------------------------------- ERROR: object X$ASH does not exist However sqlplus did (why did I try this with a GUI in the first place?) SQL> desc x$ash Name Null? Type ----------------------------------------- -------- ADDR RAW(8) INDX NUMBER INST_ID NUMBER SAMPLE_ADDR NUMBER ... Oh well, can't even blame the morning for this as it's 11:00 here. Thanks for your replies, that helped a lot! On 03/03/2010 11:08 AM, Tanel Poder wrote: > You can just DESC X$ASH to see its columns. X$ tables are not views, so > they don't have view SQL hardcoded like V$ do. > ... > Martin -- Martin Bach OCM 10g http://martincarstenbach.wordpress.com http://www.linkedin.com/in/martincarstenbach -- //www.freelists.org/webpage/oracle-l