Re: Interesting Metric

  • From: "vze1vwnd" <walter.kirsch@xxxxxxxxxxx>
  • To: <oracle-l@xxxxxxxxxxxxx>
  • Date: Tue, 30 Mar 2004 06:33:47 -0500

RE: Latch ContentionDid anyone reply?
  ----- Original Message ----- 
  From: Post, Ethan 
  To: oracle-l@xxxxxxxxxxxxx 
  Sent: Tuesday, March 02, 2004 2:16 PM
  Subject: Interesting Metric


  I have a threaded batch process running in which all the threads are pretty 
much doing the same thing.  I have another report which shows total IO, CPU, 
REDO and more by session.  When you look at this report (basically workload) 
all of the #'s and times are pretty much the same.  Meaning all of the threads 
are processing about the same amount of work.  However, if you look below I get 
these usual spikes in Buffer Busy waits and they correlate to specific 
sessions.  it looks like the spikes occur during a checkpoints.  It is strange 
because it looks like just a couple session accumulate all of the buffer busy 
time instead of all of the sessions.  


          Total   Latch  Buffer  Db File  Db File  D Path  D Path         Log 
Buf Log File SQL*Net
    SID Seconds    Free    Busy Sct Read Seq Read    Read   Write Enqueue   
Space     Sync  to Cli
  ----- ------- ------- ------- -------- -------- ------- ------- ------- 
------- -------- -------
     10       0       0       0        0        0       0       0       0       
0        0       0
      8       0       0       0        0        0       0       0       0       
0        0       0
      9       1       0       0        1        1       0       0       0       
0        0       0
     41     109       4      15        3       83       0       0       0       
0        4       0
     19     114       2       0       24       44       0       0       0       
0       44       0
     31     125       4      34        3       80       0       0       0       
0        4       0
     25     126       3      17        3       98       0       0       0       
0        5       0
     27     127       4      10        3      106       0       0       1       
0        4       0
     29     151       4      31        2      111       0       0       0       
0        3       0
     38    1784       4      26        3     1747       0       0       0       
0        3       0
     40    1788       4      28        1     1751       0       0       0       
0        4       0
     37    1941       3    1807        2      125       0       0       0       
0        4       0
     32    2053       3      19        3     2024       0       0       0       
0        4       0
     28    3578       3    1874        3     1693       0       0       0       
0        4       0
     34    3798       4      13        3     3775       0       0       0       
0        4       0
     14    4266       4      33        2     4223       0       0       0       
0        3       0
     24    4892       3       9        2     4875       0       0       0       
0        4       0
     26    5090       4      21        2     5058       0       0       1       
0        4       0
     39    5371       5      75        2     5287       0       0       0       
0        2       0
     35    6737       2      13        2     6717       0       0       0       
0        4       0
     23    7075       5    2525        2     4539       0       0       0       
0        3       0
     33    9435       3      24        2     9401       0       0       0       
0        3       0
     30    9835       3      24        3     9802       0       0       0       
0        3       0
     36   10481       4      32     2978     7463       0       0       0       
0        4       0

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