10g:計算RecoveryArea的大小

計算恢復區域的大小.
-- Determine the size you need for your recovery area
select sum(bytes) from v$datafile;-- valueA
-- Then get the total size of archivelogs over the last 24 hours
select sum(blocks*block_size) bytes from v$archived_log
where completion_time > sysdate-1;-- valueB
-- We then multiply our database size by 2, and then take the sum of the datafile and archivelog values,
-- and multiple by 1.2 to get a 20 percent increase from this size to cover file header blocks and other
-- files that may exist in this space:
((valueA * 2) + valueB) * 1.2 -- valueC

valueC is the size of your recovery area.