oracle优化求生指南脚本记录

1.查找未使用索引

/* Formatted on 2020/5/12 下午 03:32:39 (QP5 v5.163.1008.3004) */
WITH IN_PLAN_OBJECTS
     AS (SELECT DISTINCT OBJECT_NAME
           FROM V$SQL_PLAN
          WHERE OBJECT_OWNER = USER)
SELECT TABLE_NAME,
       INDEX_NAME,
       CASE WHEN OBJECT_NAME IS NULL THEN 'NO' ELSE 'YES' END
          AS IN_CACHED_PLAN
  FROM    USER_INDEXES
       LEFT OUTER JOIN
          IN_PLAN_OBJECTS
       ON (INDEX_NAME = OBJECT_NAME);

或

/*对所有索引添加MONITOR*/
BEGIN
   FOR r IN (SELECT index_name FROM user_indexes)
   LOOP
      EXECUTE IMMEDIATE 'ALTER INDEX ' || r.index_name || ' MONITORING USAGE';
   END LOOP;
END;

SELECT INDEX_NAME,
       TABLE_NAME,
       USED,
       START_MONITORING
  FROM V$OBJECT_USAGE
 WHERE MONITORING = 'YES';

2.查找数据库中应该修改为绑定变量减少硬解析的SQL

/* Formatted on 2020/5/13 下午 05:43:03 (QP5 v5.163.1008.3004) */
WITH FORCE_MATCHES
     AS (  SELECT FORCE_MATCHING_SIGNATURE,
                  COUNT (*) MATCHES,
                  MAX (SQL_ID || CHILD_NUMBER) MAX_SQL_CHILD,
                  DENSE_RANK () OVER (ORDER BY COUNT (*) DESC) RANKING
             FROM V$SQL
            WHERE FORCE_MATCHING_SIGNATURE <> 0
                  AND PARSING_SCHEMA_NAME <> 'SYS'
         GROUP BY FORCE_MATCHING_SIGNATURE
           HAVING COUNT (*) > 5)
  SELECT SQL_ID,
         MATCHES,
         PARSING_SCHEMA_NAME SCHEMA,
         SQL_TEXT
    FROM V$SQL JOIN FORCE_MATCHES ON (SQL_ID || CHILD_NUMBER = MAX_SQL_CHILD)
   WHERE RANKING <= 10
ORDER BY MATCHES DESC;