Oracle redo log 大小及组数的设置（在线修改日志组数目及组成员个数）
1.查看当前系统现有的redo log状况（组数/大小/名称/状态）
SYS@ORCL>desc v$log
Name Null? Type
----------------------------------------- -------- ----------------------------
GROUP# NUMBER
THREAD# NUMBER
SEQUENCE# NUMBER
BYTES NUMBER
BLOCKSIZE NUMBER
MEMBERS NUMBER
ARCHIVED VARCHAR2(3)
STATUS VARCHAR2(16)
FIRST_CHANGE# NUMBER
FIRST_TIME DATE
NEXT_CHANGE# NUMBER
NEXT_TIME DATE
SYS@ORCL>select GROUP# ,BYTES/1024/1024 size_M,STATUS,ARCHIVED from v$log;
GROUP# SIZE_M STATUS ARC
---------- ---------- ---------------- ---
1 50 INACTIVE YES
2 50 INACTIVE YES
3 50 CURRENT NO
SYS@ORCL>desc v$logfile;
Name Null? Type
----------------------------------------- -------- ----------------------------
GROUP# NUMBER
STATUS VARCHAR2(7)
TYPE VARCHAR2(7)
MEMBER VARCHAR2(513)
IS_RECOVERY_DEST_FILE VARCHAR2(3)
SYS@ORCL>select MEMBER from v$logfile;