Your DB_RECOVERY_FILE_DEST_SIZE IS 8G,Currently,5G of the space is used of which 4G consists of obsolete backups, You execute this command;
SQL> ALTER SYSTEM SET db_recovery_file_dest_size=2G;
What is the outcome?
A) It changes DB_RECOVERY_FILE_DEST_SIZE to 2G and deletes the obsolete backups
B) It changes DB_RECOVERY_FILE_DEST_SIZE to 5G
C) It fails because DB_RECOVERY_FILE_DEST_SIZE is a static parameter
D) It changes DB_RECOVERY_FILE_DEST_SIZE to 2G without deleting valid backups
E) It fails because the new size is less than 5G
Answer: D (驗證過)
CUUG：因爲當前還有空閒的空間 3G,所以無需刪除有效和無效的備份。
趙：網友選 A 待驗證。個人認爲有效的備份只有 1G，小於被修改後的 2G，不需要刪除過時的備份。
題譯：DB_Recovery_file_DEST_size 爲 8G，目前使用的空間爲 5G，其中 4G 由過時的備份組成。
其他：A 實測不會刪除