zoukankan      html  css  js  c++  java
  • oracle查询使用频率和磁盘消耗需要缓存大小

    SELECT *
      FROM (SELECT Sql_Text, Sql_Id, Cpu_Time FROM V$sql ORDER BY Cpu_Time DESC)
     WHERE Rownum <= 10
     ORDER BY Rownum ASC;
    
    SELECT *
      FROM (SELECT Sql_Text, Sql_Id, Cpu_Time FROM V$sqlarea ORDER BY Cpu_Time DESC)
     WHERE Rownum <= 10
     ORDER Byrownum ASC;

    这2个语句效果基本一样,一个从v$sql视图查询一个从v$sqlarea视图查询。 

    列出使用频率最高的5个查询:
    SELECT Sql_Text, Executions
      FROM (SELECT Sql_Text,
                   Executions,
                   Rank() Over(ORDER BY Executions DESC) Exec_Rank
              FROM V$sql)
     WHERE Exec_Rank <= 5;

     

    消耗磁盘读取最多的sql top5: 
    SELECT Disk_Reads, Sql_Text
      FROM (SELECT Sql_Text,
                   Disk_Reads,
                   Dense_Rank() Over(ORDER BY Disk_Reads DESC) Disk_Reads_Rank
              FROM V$sql)
     WHERE Disk_Reads_Rank <= 5;
     
    找出需要大量缓冲读取(逻辑读)操作的查询:
    SELECT Buffer_Gets, Sql_Text
      FROM (SELECT Sql_Text,
                   Buffer_Gets,
                   Dense_Rank() Over(ORDER BY Buffer_Gets DESC) Buffer_Gets_Rank
              FROM V$sql)
     WHERE Buffer_Gets_Rank <= 5;
  • 相关阅读:
    机房管理系统
    Red_Black_Tree C++
    Binary_Seach_Tree(BST) C++
    贪吃蛇小笔记
    转-Unix系统进程对SIGTERM、SIGUSR1和SIGUSR2信号处理
    My Dev Env
    mac gdb home-brew
    pub python
    ioctl siocgifhwaddr mac os x
    macbook与外接显示器
  • 原文地址:https://www.cnblogs.com/chenv/p/5390735.html
Copyright © 2011-2022 走看看