一些转储和清除内存对象和物理对象的命令(转)

9i清buffer cache
alter session set events 'immediate trace name flush_cache level 1';

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

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 '...redo01.log';

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

转储系统状态

ALTER SESSION SET EVENTS 'IMMEDIATE TRACE NAME SYSTEMSTATE LEVEL 10';

常见的有
　　1、分析数据文件块，转储数据文件n的块m
　　alter system dump datafile n block m

　　2、分析日志文件
　　alter system dump logfile logfilename;

　　3、分析控制文件的内容
　　alter session set events 'immediate trace name CONTROLF level 10'

　　4、分析所有数据文件头
　　alter session set events 'immediate trace name FILE_HDRS level 10'

　　5、分析日志文件头
　　alter session set events 'immediate trace name REDOHDR level 10'

　　6、分析系统状态，最好每10分钟一次，做三次对比
　　alter session set events 'immediate trace name SYSTEMSTATE level 10'

　　7、分析进程状态
　　alter session set events 'immediate trace name PROCESSSTATE level 10'

　　8、分析Library Cache的详细情况
　　alter session set events 'immediate trace name library_cache level 10'