I know you can reset it in the spfile with the following syntax: alter system reset db_file_multiblock_read_count scope=spfile sid='*'; But, then I ran the following test: SQL> show parameter multiblock NAME TYPE VALUE ------------------------------------ ----------- ------------------------------ db_file_multiblock_read_count integer 128 <--(this was the "unset" value that Oracle set on its own at startup) SQL> alter system set db_file_multiblock_read_count=64; <--(I changed it to a hardcoded value of 64) System altered. SQL> alter system reset db_file_multiblock_read_count scope=memory sid='baantst1'; System altered. The above command completes successfully, but below you can see the parameter is still set to 64, so it doesn't appear to have had the desired affect of forcing Oracle to dynamically calculate its own value. SQL> show parameter multi NAME TYPE VALUE ------------------------------------ ----------- ------------------------------ db_file_multiblock_read_count integer 64 Regards, Brandon Privileged/Confidential Information may be contained in this message or attachments hereto. Please advise immediately if you or your employer do not consent to Internet email for messages of this kind. Opinions, conclusions and other information in this message that do not relate to the official business of this company shall be understood as neither given nor endorsed by it. -- //www.freelists.org/webpage/oracle-l