Oracle redo日志异常增量排查 logminer 分析

1、查看日志切换次数

WITH T AS 
(
    SELECT TO_CHAR(FIRST_TIME, 'YYYY-MM-DD')    AS LOG_GEN_DAY, 
           TO_CHAR(SUM(DECODE(TO_CHAR(FIRST_TIME, 'YYYY-MM-DD'), 
                       TO_CHAR(FIRST_TIME, 'YYYY-MM-DD'), 1, 0))
                , '999') AS "LOG_SWITCH_NUM" 
    FROM   V$LOG_HISTORY 
  WHERE FIRST_TIME < TRUNC(SYSDATE)  --排除当前这一天
    GROUP  BY TO_CHAR(FIRST_TIME, 'YYYY-MM-DD') 
)
SELECT  T.LOG_GEN_DAY
          , T.LOG_SWITCH_NUM
          , M.AVG_LOG_SWITCH_NUM
      , (T.LOG_SWITCH_NUM-M.AVG_LOG_SWITCH_NUM) AS DIFF_SWITCH_NUM
FROM  T CROSS JOIN 
(
    SELECT  TO_CHAR(AVG(T.LOG_SWITCH_NUM),'999') AS AVG_LOG_SWITCH_NUM
    FROM T
) M
ORDER BY T.LOG_GEN_DAY DESC;

SELECT    TO_CHAR(FIRST_TIME,'YYYY-MM-DD') DAY,
                TO_CHAR(SUM(DECODE(TO_CHAR(FIRST_TIME,'HH24'),'00',1,0)),'999') "00",
                TO_CHAR(SUM(DECODE(TO_CHAR(FIRST_TIME,'HH24'),'01',1,0)),'999') "01",
                TO_CHAR(SUM(DECODE(TO_CHAR(FIRST_TIME,'HH24'),'02',1,0)),'999') "02",
                TO_CHAR(SUM(DECODE(TO_CHAR(FIRST_TIME,