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Range Partitioning 中VALUES LESS THAN 算法
dsi 302 lession 8The VALUES LESS THAN clause applies to all of the partitioning columns collectively. Therefore, the value in the partition key’s first column can be equal to the first column of the...
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10g synonym也可以invalid
10g之前，同义词从来不会invalid，因为没有依赖关系，10g中synonym和base之间有了依赖关系，具体可以查看视图DBA_DEPENDENCIES;导致synonym失效的原因见如下几种：This can happen for many reasons. Some of them...
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assm不仅可以减少buffer busy wait等待还可以减少itl等待
对于assm可以减少buffer busy wait中的freelist断头块争用很多文章都有提到过，今天做了个实验，对于insert操作也可以分离块的选择，对于不同的session选择不同的块进行insert，test如下create table zz（id char（...
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oracle中的userenv及sys_context的参数
1、 USERENV(OPTION) 返回当前的会话信息. OPTION='ISDBA'若当前是DBA角色,则为TRUE,否则FALSE. OPTION='LANGUAGE'返回数据库的字符集. OPTION='SESSIONID'为当前会话标识符. OPTION='ENTRYID'返回可...
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system dump-----------Library Object Lock State Object
Example: LIBRARY OBJECT LOCK: lock=30a6d48 handle=323fe98 mode=X call pin=0 session pin=0 user=302714c session=302714c count=1 flags=[00] savepoint=86 LIBRARY OBJECT HANDLE: ha...
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system dump------------Enqueue State Object
Example: (enqueue) MR-00000008-00000000 [O8: DID: <instance number>-<Oracle PID>-<sequence number> ] lv: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 res:304c7fc, mode: S, prv: 304c804, sess: 3024...
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gc cr request 'gcs log flush sync'
This is how it happens -1)You fired an update statement on Instance-2. 2)However, the request for desired blocks was gone to Instance-1. So Instance-2 was waiting on ''gc cr request'. 3)Instance-1 had...
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bind peeking
Create Table PreferredMeals (EmpID Number(5), Meal Varchar2(10) ) / Begin For i in 1..74998 Loop Insert Into PreferredMeals Values (i, 'Mansaf'); End Loop; Insert Into PreferredMeals Values (74999, '...
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invalidate the plans in shared pool
To invalidate any cursor, one of the followings can be done:1. Issue the command Alter System Flush Shared_Pool; 2. Delete or change the cursor underlying objects statistics 3. Grant...
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table 和index的parallel
在建表和索引的过程中，可以指定parallel参数来加快速度，但是很多人使用之后忘记将他们改回去，导致sql的效率低下，为了找出库中这些表和索引，我们可以使用以下语句select degree,count(*) from dba_indexes grou...
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rac 裸设备owner不一致导致的数据库hang
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批量create table出现的等待
上线过程中由于应用的需要，将大量分区非常多的分区表分成单表，于是需要批量create table，起了100个进程同时并发create table，过程中出现了大量的enq: TX - row lock contentionrow cache lockenq: TX - alloc...
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Mutexes in Oracle10g
摘要Mutexes的介绍从http://archive.netbsd.se/?ml=oracle-l&a=2006-04&t=1969601To improve cursor execution and also hard parsing, a new memory serialization mechanism has been created in 10gR2.For certai...
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cursor: pin S
OTN的解释,cursor: pin SA session waits on this event when it wants to update a shared mutex pin and another session is currently in the process of updating a shared mutex pin for the same cursor obj...
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sql plan enhancements in 10g
Since the days of Version 7, Oracle has been exposing more (and more detailed) diagnostic information to its users. Oracle was originally instrumented to assist the kernel developers with their own pe...
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kksfbc child completion & cursor: pin S
The problem seems to be the following: Session 1 gets a child cursor for a table_x_x_xxxx_x_x cursor...
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Static Service Registration (SID_LIST) Section
一直使用listener.ora中的静态注册，但一直没有系统学习其中各部分的含义，今天看到trace listener顺便学习一下You can use the SID_LIST section of the listener.ora to statically configure service informatio...
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row cache lock等待事件一例
上线前第一次预演：有多进程ctas大表的时候数据中出现了大量的row cache lock，由于前期也用同样的脚本导过一次，速度很快，就没有非空闲等待事件，所以很奇怪，既然问题出现了，只奇怪是没用的，row cache只有看看v...
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ORA-00600: internal error code, arguments: [ktadrprc-1]
忘记关recyclebin了，现在回收站占了很大的空间，想清一下回收站start time09050207:02:38 PMpurge dba_recyclebin*ERROR at line 1:ORA-00600: internal error code, arguments: [ktadrprc-1], [], [], [], [], []...
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10g Recyclebin Features And How To Disable it( _recyclebin )
Doc ID: 265253.1In this Document Purpose Scope and Application 10g Recyclebin Features And How To Disable it( _recyclebin ) ABOUT 10g...
