Oracle Buffer Cache的keep、recycle、default pool概念图解

Oracle Buffer Cache的keep、recycle、default pool概念图解

 

buffer pool

图解Oracle Buffer Cache LRU List

看了这图你该搞懂Oracle Buffer Cache原理中的LRU list (Auxiliary ) 和 LRUW List(Auxiliary)的概念了。

 

lru & lruwlru lruw lrup lruxo


 

 

一张图帮你搞懂oracle UGA User Global Area的概念

一张图帮你搞懂oracle UGA的概念 User Global Area

 

uga

Oracle latch闩原理示意图

还是搞不懂oracle中latch 闩的原理吗?那么来看看这个图 以及下面这段代码如何?

 

latch

 

Function Get_Latch(latch_name,mode)
{
  If Mode eq ‘immediate’ {
    If Fast_Get(latch_name) {
      return TRUE
    Else {
      return FALSE
    }
  }
  Else {
    If Fast_Get(latch_name)
    Then {
      v$latch.gets++
      return TRUE
    }
    Else {
      v$latch.misses++
      for try = 0 .. large_number
      {
        if Spin_Get(latch_name)
        Then {
          return TRUE
        }
        Else {
          T0 = time
          Sleep(try)
          T1=time
          Register_Event("latch free",T1-T0)
        }
      } -- spin/sleep loop
    }
  }
}

Function Fast_Get(latch_name)
{
  If try_to_get_latch(latch_name)
  Then {
    return TRUE
  }
  Else {
    return FALSE
  }
}

Function Spin_Get(latch_name)
{
  v$latch.spin_get++
  for i = 1 to _spin_count
  {
    If Fast_Get(latch_name)
    Then {
      return TRUE
    }
  }
}

Function Sleep(try)
{
  v$latch.sleeps++
  v$latch.sleep[try]++
  sleeptime =
    decode(try,0,0,1,10,2,20,3,~40,4,~80,...~2000)
  sleep(sleeptime)
}

Oracle Unbreakable Enterprise Kernel Faster than Redhat?

Oracle Unbreakable Enterprise Kernel Faster than Redhat? Oracle 在宣传其 牢不可破企业Linux内核时总是要和Redhat 做个比较, 并拿自己测得一个benchmark 来说事, 在这个chart里UEK 比redhat kernel 快75%!

 

Oracle Buffer Cache Chain图解

Oracle Buffer Cache Chain图解

buffer cache chain hash

看看MySQL几种主流备份方案的优缺点

看看MySQL几种主流备份方案的优缺点,Mysql Available Backup Solutions

 

The V$ Views For Oracle Database 11gR2

11gR2的 V$ view 动态视图一览图, 很可惜目前只有这个模糊版的:

 
The V$ View FOR ORACLE DATABASE 11gR2

一个DBA的工作写照

一个DBA的工作写照, 一个DBA的内心 Know the DBA Mind!

 

 

 

DBA也是 IT民工啊, 民工何苦为难民工!

 

 

DBA眼中的自己和开发者眼中的DBA

DBA眼中自己的形象:

 

This is How DBA View Themselves!

 

开发者眼中DBA的形象: 愤怒的厨师!

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