RE: excessive number of db writer

  • From: "Laimutis Nedzinskas" <Laimutis.Nedzinskas@xxxxxxxxxxxxx>
  • To: <oracle-l@xxxxxxxxxxxxx>
  • Date: Wed, 6 Sep 2006 17:19:55 -0000

> From: oracle-l-bounce@xxxxxxxxxxxxx
[mailto:oracle-l-bounce@xxxxxxxxxxxxx] On Behalf Of Kevin 
> As an aside, and as usual for the sake of history, the idea of
multiple writers (processes that build their own write batches) was not
considered until the dawn of NUMA systems in the mid-to-late  90s. See,
having a single writer build batches and task slaves is absolute murder
on a NUMA system. All dbwr latching activity had to take place in the L3
of the building block where dbwr happened to be running. It was, um,
horrible. So, Tirthanker Lahiri listened to our findings and analysis of
our bus traces and implemented multiple true database
nice. There is more info about that in James Morle's book...

Is it known what exactly is the difference between Oracle's dbwr
"master-slaves" and "mutiple dbwr"? As far as I understand it is about
making access to LRU *parallel* by adding multiply LRU lists, isn't it?

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