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1. How does the invalid object come?The Oracle database will invalidate objects if a dependent object is changed. If I rebuild a table, the indexes on... 阅读全文
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十进制与十六进制的转换十进制-->十六进制select to_char(100,'XX') from dual;十六进制-->十进制select to_number('7D','XX') from dual; 阅读全文
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Example to show the dead lock caused by lack of index on foreign key of child table.Session 1:create table p ( x int primary key );create table c ( x ... 阅读全文
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http://blog.csdn.net/liqfyiyi/article/details/7727641http://www.askmaclean.com/archives/category/oracle/lockhttp://database.51cto.com/art/201004/19729... 阅读全文
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1. enable traceDBCC TRACEON (trace# [ ,...n ][ , -1 ] ) [ WITH NO_INFOMSGS ]trace# Is the number of the trace flag to turn on.n Is a placeholder that... 阅读全文
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转自http://blog.csdn.net/biti_rainy/article/details/35188热点块的定义 数据库的热点块，从简单了讲，就是极短的时间内对少量数据块进行了过于频繁的访问。定义看起来总是很简单的，但实际在数据库中，我们要去观察或者确定热点块的问题，却不是那么简单了。要深... 阅读全文