自动收集执行计划
此只收集过期的统计信息。
可以放到linux crontab里，每隔一天运行一次。
DECLARE
CURSOR STALE_TABLE IS
SELECT OWNER,
SEGMENT_NAME,
CASE
WHEN SIZE_GB < 0.5 THEN
30
WHEN SIZE_GB >= 0.5 AND SIZE_GB < 1 THEN
20
WHEN SIZE_GB >= 1 AND SIZE_GB < 5 THEN
10
WHEN SIZE_GB >= 5 AND SIZE_GB < 10 THEN
5
WHEN SIZE_GB >= 10 THEN
1
END AS PERCENT,
8 AS DEGREE
FROM (SELECT OWNER,
SEGMENT_NAME,
SUM(BYTES / 1024 / 1024 / 1024) SIZE_GB
FROM DBA_SEGMENTS
WHERE OWNER = 'ADWU_OPTIMA_AP11'
AND SEGMENT_NAME IN
(SELECT /*+ UNNEST */ DISTINCT TABLE_NAME
FROM DBA_TAB_STATISTICS
WHERE (LAST_ANALYZED IS NULL OR STALE_STATS = 'YES')
AND OWNER = 'ADWU_OPTIMA_AP11')
GROUP BY OWNER, SEGMENT_NAME);
BEGIN
DBMS_STATS.FLUSH_DATABASE_MONITORING_INFO;
FOR STALE IN STALE_TABLE LOOP
DBMS_STATS.GATHER_TABLE_STATS(OWNNAME => STALE.OWNER,
TABNAME => STALE.SEGMENT_NAME,
ESTIMATE_PERCENT => STALE.PERCENT,
METHOD_OPT => 'for all columns size repeat',
DEGREE => 8,
GRANULARITY => 'ALL',
CASCADE => TRUE);
END LOOP;
END;
/