http://space.itpub.net/9240380 Copyright(C) wisdomone1的个人空间 SupeSite/X-Space Sat, 11 Oct 2008 12:03:29 GMT http://space.itpub.net/9240380/viewspace-350575 已经采用:nologging
        parallel
       &nb...]]> blog wisdomone1 Wed, 04 Jun 2008 20:26:59 GMT http://space.itpub.net/9240380/viewspace-350574

大家好,客户网站,现在开发人员反应在java代码中内含的insert语句,每天并发高达8000w-1亿记录之间,对于这种高并发性(随机性),有何优化方法.
已经采用:nologging
  &...]]> blog wisdomone1 Wed, 04 Jun 2008 20:25:24 GMT http://space.itpub.net/9240380/viewspace-350573 已经采用:nologging
        parallel
       &nb...]]> blog wisdomone1 Wed, 04 Jun 2008 20:21:12 GMT http://space.itpub.net/9240380/viewspace-350572 大家有什么办法.我查了好像clone database,也要停机,哪位坛友作...]]> blog wisdomone1 Thu, 29 May 2008 14:42:45 GMT http://space.itpub.net/9240380/viewspace-350571

我是这么理解的:
db_name:比如我安装数据库软件,然后用dbca建库,一个库对应一个db_name
instance_name:一个db_name可以有多个instance_nam...]]> blog wisdomone1 Mon, 26 May 2008 22:43:42 GMT http://space.itpub.net/9240380/viewspace-350570 范围：限opensystem和windows
版本：Version 0.1 build 20060904

说在前面的几句话:
我工作的时间也不短了,但是还算是一个老菜鸟,所以我姑妄说之,您姑妄听之.另外,我也是想到哪儿写道哪儿,没什么章法,还望海...]]> blog wisdomone1 Thu, 22 May 2008 01:33:35 GMT http://space.itpub.net/9240380/viewspace-350569 Every 1 out of 100 people using Oracle believes using count(*) is slower than either count(<a constant number>), count(<primary key column>) or count(rowid); 1 out of 1...]]> blog wisdomone1 Wed, 21 May 2008 23:44:32 GMT http://space.itpub.net/9240380/viewspace-350568 众所周知，Table是分区的时候，analyze根据所有partition上的已有的统计信息“计算”出整个表级别上的统计信息；而dbms_stats是实际去计算整个表范围的统计信息，因此表级别的统计信息比analyze更精确，反映表上真实的情况.

...]]> blog wisdomone1 Wed, 21 May 2008 23:01:40 GMT http://space.itpub.net/9240380/viewspace-350567 角色可以grant给任何其他的用户或者角色，但不能grant给它自己，角色不能循环授权。角色不属于任何schema，但它在数据字典中有描述。
role 没有schema（即owener），所以对于SYS建立的role，其他的用户也可以对...]]> blog wisdomone1 Tue, 20 May 2008 23:49:24 GMT http://space.itpub.net/9240380/viewspace-350566 ...]]> blog wisdomone1 Sat, 17 May 2008 03:22:50 GMT http://space.itpub.net/9240380/viewspace-350564 利用DBMS_FILE_TRANSFER传输数据库文件
作者：流云 | 【转载时请务必以超链接形式标明文章原始出处和作者信息及本声明】
地址：http:/...]]> blog wisdomone1 Sat, 17 May 2008 02:26:05 GMT http://space.itpub.net/9240380/viewspace-350563 s(课程表)        (cno 课程号,cname 课程名,cteacher 认课老师)
s_c(选课关系表)  (sno 学号,cno 课程号,cgrade 课程成绩)

...]]> blog wisdomone1 Fri, 16 May 2008 23:53:09 GMT http://space.itpub.net/9240380/viewspace-350562         at java.util.zip.ZipInputStream.readEnd(Unknown Source)
        at java.util.zip.ZipInputStream.read(U...]]> blog wisdomone1 Fri, 16 May 2008 01:16:47 GMT http://space.itpub.net/9240380/viewspace-350561 begin
open :x for select username from dba_users;
end;
/
print x;


variable scn number
exec :scn:=dbms_flashback.get_system...]]> blog wisdomone1 Wed, 14 May 2008 11:20:54 GMT http://space.itpub.net/9240380/viewspace-350560 1.ASCII
返回与指定的字符对应的十进制数;
SQL> select ascii('A') A,ascii('a') a,ascii('0') zero,ascii(' ') space from dual;

        A        &...]]> blog wisdomone1 Tue, 13 May 2008 13:47:38 GMT http://space.itpub.net/9240380/viewspace-350559 意思就是：
文件系统是操作系统与驱动器之间的接口，当操作系统请求从硬盘里读取一个文件时，会请求相应的文件系统（FAT 16/32/NTFS）打开文件。扇区是磁盘最小的物理存储单元，但由于操作系统无法对数目众多的扇区进行寻址，所以...]]> blog wisdomone1 Sat, 10 May 2008 00:15:42 GMT http://space.itpub.net/9240380/viewspace-350558 大家给支支招,
1 ,想到的办法:
   对表进...]]> blog wisdomone1 Fri, 09 May 2008 17:49:26 GMT http://space.itpub.net/9240380/viewspace-350557 capture process rules
local capture and downstream capture
streams capture processes and oracle rac
capture process can run on the source database(local capture process) or on a remote database(downs...]]> blog wisdomone1 Thu, 08 May 2008 21:20:16 GMT http://space.itpub.net/9240380/viewspace-350556
详细解读 STATSPACK 报告 1
1、报表头信息 2
2、实例负载档信息 2
3、实例有效性信息 3
4、TOP 5及其他等待事件信息 5
5、SQL统计信息 10
5.1 SQL统计信息－逻辑读 11
5.2 SQL统...]]> blog wisdomone1 Mon, 28 Apr 2008 00:55:51 GMT http://space.itpub.net/9240380/viewspace-350555
alter system set timed_statistics=true;---收集os的计时信息,存储在v$sesstats and v$sysstats


install statspack
run as sysdba
be better to ...]]> blog wisdomone1 Sun, 27 Apr 2008 03:00:53 GMT http://space.itpub.net/9240380/viewspace-350554
-----查系统表空间非系统用户的索引情况
select count(*)
from dba_indexes
where tablespace_name='SYSTEM' and owner not in('SYS','SYSTEM');

select table_name,index_name
from dba_i...]]> blog wisdomone1 Sun, 27 Apr 2008 02:16:46 GMT http://space.itpub.net/9240380/viewspace-350553

log file switch(archiving needed)----在conn trans/system; insert into test select * from test;---500万记录时


select na...]]> blog wisdomone1 Sun, 27 Apr 2008 00:59:46 GMT http://space.itpub.net/9240380/viewspace-350552 在些基础上作了一些centos,rhel5(4)上oracle10g(oracle9i)的...]]> blog wisdomone1 Sat, 26 Apr 2008 17:49:06 GMT http://space.itpub.net/9240380/viewspace-350551 每周作一次增累备份,每月作一次全库备份,这样是否合理.
还有一个问题,请问大家针对这样的数据量,如何制订数据备份.]]> blog wisdomone1 Thu, 24 Apr 2008 22:51:32 GMT http://space.itpub.net/9240380/viewspace-350550
1).Global Area

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

1 包含PGA
2 包含SGA
4 包含UGA
8 包含indrect memory

2).Library Cache
blog wisdomone1 Tue, 22 Apr 2008 04:20:22 GMT http://space.itpub.net/9240380/viewspace-350549 March 13, 2008 – 4:16 pm
做了个10G中的压缩表测试，发现压缩比例还是比较高的，关键看数据是否按照重复性高的列在排序
也对压缩表和非压缩表查询进行了对比，测试结果表明解压还是存在不少的CPU消耗，时间居然比普通表要久，...]]> blog wisdomone1 Fri, 18 Apr 2008 23:29:52 GMT http://space.itpub.net/9240380/viewspace-350548 2，增量备份:<=n   同级备份很多，更多恢复时间（因为要转储更多的备份集）,减少了备份时间
                backup...]]> blog wisdomone1 Sun, 13 Apr 2008 18:29:01 GMT http://space.itpub.net/9240380/viewspace-350547
INFO: Method 'dispose()' Not implemented in class 'ConfigurationOptions'
INFO: config-context initialized
INFO: *** Install Page***
INFO: FastCopy : File Version is Compatible
INFO:...]]> blog wisdomone1 Fri, 11 Apr 2008 02:12:52 GMT http://space.itpub.net/9240380/viewspace-350546 select distinct sid from v$mystat;
select spid from v$process where addr=(select paddr from v$session where sid=(select distinct sid from v$mystat));
execute dbms_session.set_...]]> blog wisdomone1 Wed, 09 Apr 2008 22:08:07 GMT