当前位置: 首页 > 图文教程 > 数据库 > Oracle > Performance Improvement Tips for Oracle on UNIX

Oracle
oracle sys_connect_by_path 函数 结果集连接
oracle join on 数据过滤问题
Oracle 当前用户下所有表的记录总数
oracle 树查询 语句
oracle 触发器 实现出入库
Oracle 函数大全
oracle 删除重复数据
ORACLE 最大连接数的问题
oracle 层次化查询(行政区划三级级联)
oracle 查询表名以及表的列名
Oracle 数据显示 横表转纵表
oracle 服务启动,关闭脚本(windows系统下)
ORCLE 表中列的修改
oracle 数据库连接分析
Oracle 实现类似SQL Server中自增字段的一个办法
Oracle 常用的SQL语句
Oracle 数组的学习 小知识也要积累,养成好的学习态度
Oracle 日期的一些简单使用
Oracle 数据库连接查询SQL语句
Oracle DBA常用语句

Performance Improvement Tips for Oracle on UNIX


出处:互联网   整理: 软晨网(RuanChen.com)   发布: 2009-10-31   浏览: 50 ::
收藏到网摘: n/a

TIMED_STATISTICS = true

  1. Restart your database. 
  2. Run your application.
  3. Run tkprof against the tracefile created by your application:

tkprof EXPLAIN=username/passwd

  1. Look at formatted output of trace command and make sure that your

      SQL statement is using indexes correctly.  Refer to DBA guide for a list

      of rules that the oracle optimizer uses when choosing a path for a SQL statement. 

                 <<<<<< OUTPUT OF TKPROF FILE >>>>>>> 

count   = number of times OPI procedure was executed 

cpu     = cpu time executing in hundredths of seconds 

elap    = elapsed time executing in hundredths of secs 

phys    = number of physical reads of buffers (from disk) 

cr      = number of buffers gotten for consistent read 

cur     = number of buffers gotten in current mode (usually for update) 

rows    = number of rows processed by the OPI call 

===========================================================

select * from emp where empno=7369  

            count     cpu    elap    phys      cr     cur    rows 

Parse:          1       0       0       0       0       0 

Execute:        1       0       0       0       0       2       0 

Fetch:          1       0       0     219     227       0       2 

Execution plan: 

TABLE ACCESS (FULL) OF EMP 

===========================================================

select empno from emp where empno=7934  

            count     cpu    elap    phys      cr     cur    rows 

Parse:          2       0       0       0       0       0 

Execute:        2       0       0       0       0       2       0 

Fetch:          2       0       0       0&nb