library cache pin waits

On my 9205 database, whenever I update huge number (eg. 1,000,000) of rows, other sessions will be waiting on library cache pin/lock. The column I'm updating is varchar2(1) and the buffer cache is 10GB.

eg of the update statement:
update mytable set status='P';

My understanding is library cache pin is acquired on an object if a session wants to modify the object to prevent other sessions from modifying the same object. In my case, the table is created and solely used by my schema. I'm not sure why other sessions are waiting on library cache pin/lock then. Apparently I'm not understanding something. Can someone please explain.

thanks.

Tiffany Received on Fri Oct 14 2005 - 12:03:48 CDT