Archive file format LOG_ARCHIVE_FORMAT is defined as arch_%s.arc. A week ago， you just archived arch_4.arch to tape， then removed all archived files to save disk space. Yesterday you saw arch_10.arc and arch_11.arc on the disk. Today， you see arch_3.arc in the archive directory. Which two could you happened？（）
- ARedo logs were restored from tape for recovery.
- BThe file names are only used when they are copied to tape.
- CThe database was opened with the RESETLOGS option and log numbers restarted.
- DLog names run in circular fashion; arch_3.arc is re-created by the ARCn process.
- EA file name is randomly chosen by the archive process; as long as it is unique, it does not have to be sequential.