Oracle DBA学习路径图

Oracle DBA学习路径图

 

mos support of oracle

Oracle Shared pool内存管理图解

Oracle Shared pool内存管理图解, 解释了包括 Heap、Extent、reserved List、Free List、bucket、chunk这几个概念:

 

 

shared pool 原理还可以参考下这个帖子:http://t.askmaclean.com/thread-272-1-1.html

图解Oracle Free Buffer Wait 等待事件

图解Oracle Free Buffer Wait 等待事件

 

free buffer waits

Oracle Row cache lock图解

Oracle Row cache lock(dictionary cache)图解

 

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 Buffer Cache Chain图解

Oracle Buffer Cache Chain图解

buffer cache chain hash

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

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