object table 表2
create table stu (id number, stu studentobj);
insert into stu values(1,studentobj(1,'Jack','Smith','aaaaaa',null));
insert into stu values(2,studentobj(2,'mary','Smith','aaaaaa',null));
insert into stu values(2,studentobj(5,'mary','Smith','aaaaaa',null));
commit;
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不堪重用Piero
98年世界杯,不在状态........
2000年欧洲杯,决赛浪费两次单刀,成为意大利罪人!
2002年世界杯,进了一个无关同样的远射......
2004年,仍然惨不忍睹
2006年,获得世界杯,单好象仍然与他无关
2008年.......没有登场,却已经闭幕..........
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timestamp 的存储与timestamp with timezone
Timestamp with time zone是指当地时区与格林尼制时间的偏移。
SQL> create table t_timestamp(t1 date,
t2 timestamp(9),
t3 timestamp(9) with local time zone,
t4 timestamp(9) with time zone)
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幸亏发生地震的地方不是山东
山东作协副主席王兆山先生发表于齐鲁晚报的江城子:
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背不背,看看法国队
点儿背到家了!
10分钟:里贝里受伤;
30分钟: 阿比达尔制造了点球,并且被罚下
70分钟: 亨利.......
真是运气坏透了!
还好,我是意大利的忠实拥趸.........
感谢荷兰.......
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dual 表引起create materialized view 的ora-1422
关于dual表的链接
http://songhefei.itpub.net/post/7281/216328
http://songhefei.itpub.net/post/7281/463102
create materilized view 时报 ora-1422错误
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Oracle parallel recovery
In a serial recovery scenario, the SMON background process both reads the redo log files and applies the changes to the datafiles. This may take a considerably long time when multiple datafiles need to be recovered. However, when parallel recovery is being used, the SMON process is responsible only for reading the redo log files. The changes are applied to the datafiles by multiple parallel slave processes, thereby reducing the recovery time.
Recovery requires that the changes be applied to the datafiles in exactly the same order in which they occurred. This is achieved by single-threading the read phase of the recovery process by the SMON process. SMON reads the redo log files and serializes the changes before dispatching them to the parallel slave processes. The parallel slave processes then apply those changes to the datafiles in the proper order. Therefore, the reading of the redo log files is performed serially even during a parallel recovery operation.
读redo log 肯定是lgwr 的时,而smon 只是进行分发,我想肯定要file_id,block_id进行hash 的,否则cache buffer chains 的latch 竞争一定会非常严重,影响parallel的效率!
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dual 小研究
上一篇:
http://songhefei.itpub.net/post/7281/216328
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众志成城,共度难关!
众志成城,共度难关!
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分布事务执行计划问题
local: Oracle9.2.0.1
remote :Oracle9.2.0.6
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好累!
全力备战系统分析师的考试,真是累!
书到用时方恨少!
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object table 的存储
一点小研究
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