-
编辑 删除
vacabulary
greasy:oily and saltyartificially:man-madeundercarriage:help the plan to land on safelyaeroflot: Russion civil aviation
-
编辑 删除
vacabulary
mechanicscrapedinfantcontaminated
-
编辑 删除
common wait event
db file parallel read :It has no relation with parallel read and parallel DML,It just appear in that priod when doing recover and some server process read noncontinue oracle blocks within one or...
-
编辑 删除
vacabulary
I will tan that boylimbs
-
编辑 删除
How to pass an exam
A good way to pass a exam is to work hard everyday.you may fail an exam if you are lazy for most of the year.If you want to be good at English,you have ...
-
编辑 删除
vacabulary
I wans under the impression renovateas you probably are awaresubmarinessymptomsrescue squadthat was supposed to happenmortgage(抵押）giant (巨大的）avert （防止，避免转移）potential (...
-
编辑 删除
my idear of smoking
If you take notice in places,you will recognize that most of smokers are young people,even middle school students.It's said in China there are 0.3 bilion people smoking.why do they s...
-
编辑 删除
play computer games
As a famous saying 'everything has two sides,advatages and disadvatages.computer games are no exceptions.on the one hand,computer games can stimulate your im...
-
编辑 删除
stream
配置stream中。
-
编辑 删除
准备好了两可测试库，准备做downsteam捕获的相关测试
rman 的duplicate target database确实是一个不错的命令，两个数据库很快全部搞定。由于这两个库建立分别建立在rac node的本地硬盘，在创建的时候为了图省事，两个数据库的名字都叫myt1，结果启动的时候报ORA-00304:...
-
编辑 删除
generation gap
Young people are ofen unhapply with their parents.They think their parents don't understand him.they feel that their parents are too strict with them.parents often find it dif...
-
编辑 删除
ORACLE 版本升级问题
1.升级时候一定要明确，对于使用analyze table的时候会分析索引信息的，但是dbms_stats不会。2.oracle 10g method_opt的默认值为for all columns size auto，那么我们可能会得到错误的直方图信息。3.oracle 10g会...
-
编辑 删除
ORACLE CBO 的工作原理
ORACLE 8I中CBO在获取一个表的选择度的时候，只会去考虑user_tab_col_statistics.num_distinct的值去生成COST，而对于ORACLE 9I和10g，如果没有histogram则使用rows/num_distinct生成cost...
-
编辑 删除
English(morning)
Mark and Helen run import-export company.she has decided to investigate the benefits of sea cargo over air freight.I was under the impression that your father never wanted his cargo to go by sea.Ma...
-
编辑 删除
flash back在ORACLE 数据库中的使用
ORACLE 9I中的flash back完全依赖于AUM，而且对于drop 以及truncate 等操作也是无能为力的，并且受到回滚表空间大小的限制，能够闪回的时间也是有限制的。一般的语法为：select * fr...
-
编辑 删除
2007-07-21(morning)
Buying a new car is not a easy task,especially you have a old car to trade in.Doug stuck the deal with the sales man.Recently I noticed my furniture looked torn and shabbyDo you have any spec...
-
编辑 删除
English Corner 2008-07-16
He is a hero of Indian,who is favotite of nonviolence,fight againt BITISH rule.he is a saint and be stict with himself and he take great pains to build...
-
编辑 删除
高可用性环境中的并发性
在一个繁忙的OLTP数据库中，最重要的特性莫过于并发性和一致性的控制。它的实现主要是靠lock来实现的，通常意义的lock包括如下几种： TM LOCK，这种lock在...
-
编辑 删除
在高并发和高负载环境下的数据维护
有的时候在数据维护的时候，往往会导致一些非常严重的逻辑性错误，例如避免丢失更新，千万不要认为update中a.userid=b.userid就万事大吉。如果一定要用游标方式来进行更...
-
编辑 删除
DMT到LMT 转变过程中ORACLE 内部所执行的操作。
今天做一个数据库的优化项目，主要是清理业务产生的垃圾数据，在优化的过程中，发现很多要清理的表都落在了DMT上了，应此在truncate 一些业务表的时候，导致了enqueue ST的所，于是就想到了：使用dbms_space_admin.t...
