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  • 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);

    /*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;
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  • 原文地址:https://www.cnblogs.com/monkey6/p/12876681.html
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