Unloading the rarely used column tables on to the persistent layer ?

Hello Folks,

Can someone please let me know how to unload the column tables of a particular schema that are not being used every now and then, on to the persistent layer?

eg: UNLOAD "SCHEMA_NAME"."TABLE_NAME" will unload only a particular table on to the disk, but how do i select the tables that were inactive say since the last 1 week of a particular schema.

Thanks in advance.

Regards,

Krishna