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

Oracle
Excel VBA连接并操作Oracle
Oracle 外连接实现代码
oracle 存储过程和函数例子
Oracle 数据库操作类
ORACLE 分区表的设计
Oracle 用户权限管理方法
Oracle In和exists not in和not exists的比较分析
利用windows任务计划实现oracle的定期备份
ORACLE11g随RHEL5系统自动启动与关闭的设置方法
在oracle 数据库查询的select 查询字段中关联其他表的方法
plsql和tsql常用函数比对
plsql与tsql的语法不同
ASP.NET调用oracle存储过程实现快速分页
执行drop表操作后数据库无法起动
分析Oracle有时会用索引来查找数据的原因
数据从MySQL迁移到 Oracle的注意事项
快速理解Oracle归档模式的命令及参数
在Oracle里加快SQL执行的三种方法
几条常见的数据库分页 SQL 语句
Oracle9I OCP认证过程

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: 55 ::
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