轻松掌握一些清内存对象及转储的常用命令

来源：赛迪网    作者：39033

一些清内存对象及转储的实用命令：

Oracle 9i清buffer cache

alter session set events 'immediate trace name flush_cache level 1';
alter session set events = 'immediate trace name flush_cache';

Oracle 10g中清buffer cache

alter system flush buffer_cache

清shared pool

alter system flush shared_pool;

转储sga

alter session set events 'immediate trace name heapdump level 2';

转储library cache

ALTER SESSION SET EVENTS 'immediate 
trace name LIBRARY_CACHE level n';

Level =1 ,转储Library cache统计信息

Level =2 ,转储hash table概要

Level =4 ,转储Library cache对象，只包含基本信息

Level =8 ,转储Library cache对象，包含详细信息(包括child references,pin waiters等)

Level =16,增加heap sizes信息

Level =32,增加heap信息

转储控制文件、日志文件、数据文件：

alter session set events 'immediate trace name controlf level 10';
alter session set events 'immediate trace name redohdr level 3';
ALTER SYSTEM DUMP LOGFILE '/opt/oracle9/oradata/testora9/redo01.log';
alter system dump datafile 3 block max 2 block min 4;