Ric and Connor gave you the mechanics of this. But I suspect from the way you phrased your question that the difference between a table that Oracle is protecting from changes (READ ONLY table) and a tablespace that you don't have to back up any more. mwf _____ From: oracle-l-bounce@xxxxxxxxxxxxx [mailto:oracle-l-bounce@xxxxxxxxxxxxx] On Behalf Of Orlando L Sent: Wednesday, July 07, 2010 11:20 AM To: oracle-l@xxxxxxxxxxxxx Subject: 11g READ ONLY table List Does anyone know how 11g is able to convert read write tables to READ ONLY and back when the extents are all over mixed in with other tables in a tablespace? Orlando.