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How to control CF calculation

Posted by admin on 14th May 2013

根据Richard Foote的文章,做了如下验证：

Ref：Clustering Factor Calculation Improvement and provide some control over DBMS_STATS index clustering factor computat[......]

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Active dataguard tips

Posted by admin on 23rd January 2013

11g ADG 给了大家更多的灾备选择,包括之前美国飓风,给了ADG大放光彩的机会,但是ADG并没有想象中的那么完美,以下是最近的一个CASE,具体过程不详写了,目前这个case还在跟进中,记录之：

[oracle@dcb-srv-0174 trace]$ cat itemstd02_ora_[......]

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Capture binds always actually ?

Posted by admin on 28th August 2012

我们可以通过v$sql_bind_capture 捕获到 bind values 这篇文章主要阐述v$sql_bind_capture与v$sql_plan的一些联系

SQL*Plus: Release 11.2.0.3.0 Production on Tue Aug 28 14:07[......]

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some change in cache buffer handle

Posted by admin on 7th June 2012

今天开发因为连接数不够 强烈要求加大processes值,突然想到了processes对_cursor_db_buffers_pinned的影响,,小记之:

当会话需要pin住buffer header时它首先要获去buffer handle,实例所存在的buffer handle总数由(ea[......]

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Oracle latch internals

Posted by admin on 6th June 2012

Oracle latch internals

Server latch implementation called KSL, e.g. every table with name starting with x$ksl... is latch
related and every SGA has ksl... structure as well.  In order to get complete list of x$ksl table,
connect with sysdba permissions to oracle and run query:
 
SELECT kqftanam
FROM x$kqfta
WHERE  kqftanam  LIKE 'X$KSL%'

eg:

[oracle@testdb ~]$ ora si
 
SQL*Plus: Release 11.2.0.3.0 Production on Thu Jun 6 15:37:53 2013
 
Copyright (c) 1982, 2011, Oracle.  All rights reserved.
 
 
Connected to:
Oracle Database 11g Enterprise Edition Release 11.2.0.3.0 - 64bit Production
With the Partitioning, OLAP, Data Mining and Real Application Testing options
 
SQL> SELECT kqftanam
FROM x$kqfta
WHERE  kqftanam  LIKE 'X$KSL%'      2    3  ;
 
KQFTANAM
------------------------------
X$KSLLTR
X$KSLHOT
X$KSLLCLASS
X$KSLECLASS
X$KSLEMAP
X$KSLLD
X$KSLED
X$KSLCS
X$KSLSCS
X$KSLES
X$KSLSESHIST
 
KQFTANAM
------------------------------
X$KSLEI
X$KSLLW
X$KSLPO
X$KSLWSC
X$KSLWH
X$KSLWT
 
17 rows selected.

There are two structures associated with a latch in KSL – ksl[......]

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